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Author SHA1 Message Date
Hamza Mahfooz
bed6e04be8 netfilter: conntrack: tcp: do not force CLOSE on invalid-seq RST without direction check
An unintended behavior in the TCP conntrack state machine allows a
connection to be forced into the CLOSE state using an RST packet with an
invalid sequence number.

Specifically, after a SYN packet is observed, an RST with an invalid SEQ
can transition the conntrack entry to TCP_CONNTRACK_CLOSE, regardless of
whether the RST corresponds to the expected reply direction. The relevant
code path assumes the RST is a response to an outgoing SYN, but does not
validate packet direction or ensure that a matching SYN was actually sent
in the opposite direction.

As a result, a crafted packet sequence consisting of a SYN followed by an
invalid-sequence RST can prematurely terminate an active NAT entry. This
makes connection teardown easier than intended.

So, tighten the state transition logic to ensure that RST-triggered
CLOSE transitions only occur when the RST is a valid response to a
previously observed SYN in the correct direction.

Cc: stable@vger.kernel.org
Fixes: 9fb9cbb108 ("[NETFILTER]: Add nf_conntrack subsystem.")
Signed-off-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
2026-05-22 12:27:55 +02:00
Bartosz Golaszewski
215c90ee65 device property: set fwnode->secondary to NULL in fwnode_init()
If a firmware node is allocated on the stack (for instance: temporary
software node whose life-time we control) or on the heap - but using a
non-zeroing allocation function - and initialized using fwnode_init(),
its secondary pointer will contain uninitalized memory which likely will
be neither NULL nor IS_ERR() and so may end up being dereferenced (for
example: in dev_to_swnode()). Set fwnode->secondary to NULL on
initialization.

Cc: stable <stable@kernel.org>
Fixes: 01bb86b380 ("driver core: Add fwnode_init()")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://patch.msgid.link/20260506115701.23035-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 12:24:08 +02:00
Christoph Hellwig
988c918b81
minix: release the sb buffer_head when setting the v3 block size fails
At this point the superblock is already read, so jump to the label that
releases the buffer_head for it.

Fixes: d893fc670546 ("minix: handle set_blocksize failures")
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260518130330.529085-1-hch@lst.de
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-22 12:20:49 +02:00
Xiaolei Wang
3677041715 misc: rp1: Send IACK on IRQ activate to fix kdump/kexec
After a kexec/kdump reboot, the macb Ethernet controller fails to
receive any packets, causing DHCP to hang indefinitely and the network
interface to be unusable despite link being up.

The root cause is that RP1's level-triggered MSI-X interrupt sources
(such as macb on hwirq 6) may have their internal state machines stuck
in the "waiting for IACK" state. This happens because the previous
kernel crashed before sending the acknowledgment for a pending level
interrupt.

In this stuck state, RP1 will not generate new MSI-X writes even though
the interrupt source remains asserted. Since no new MSI-X is sent, the
GIC never sees a new edge, the chained IRQ handler is never invoked,
and the interrupt is permanently lost.

Fix this by sending MSIX_CFG_IACK in rp1_irq_activate(). This
unconditionally resets the MSI-X state machine back to idle when a
child device requests its interrupt. If the interrupt source is still
asserted, RP1 will immediately issue a new MSI-X with the freshly
configured msg_addr/msg_data, and normal interrupt delivery resumes.

Writing IACK when the state machine is already idle (i.e., on a normal
cold boot) is harmless — it has no effect.

Fixes: 49d63971f9 ("misc: rp1: RaspberryPi RP1 misc driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com>
Link: https://patch.msgid.link/20260518073405.2115003-1-xiaolei.wang@windriver.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 12:19:02 +02:00
Hongling Zeng
2eae90a457 gpib: cb7210: Fix region leak when request_irq fails
When request_irq() fails, the region allocated by request_region()
is not released. Fix this by adding an error handling path with
proper goto labels to release the region.

Fixes: e9dc69956d ("staging: gpib: Add Computer Boards GPIB driver")
Closes: https://lore.kernel.org/oe-kbuild-all/202605160620.ReBOadPX-lkp@intel.com/
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20260518022939.16881-1-zenghongling@kylinos.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 12:19:02 +02:00
Ben Hutchings
ef15ccbb3e parport: Fix race between port and client registration
The parport subsystem registers port devices before they are fully
initialised, resulting in a race condition where client drivers such
as lp can attach to ports that are not completely initialised or even
being torn down.

When the port and client drivers are built as modules and loaded
around the same time during boot, this occasionally results in a
crash.  I was able to make this happen reliably in a VM with a
PC-style parallel port by patching parport_pc to fail probing:

> --- a/drivers/parport/parport_pc.c
> +++ b/drivers/parport/parport_pc.c
> @@ -2069,7 +2069,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base,
>  	if (!p)
>  		goto out3;
>
> -	base_res = request_region(base, 3, p->name);
> +	base_res = NULL;
>  	if (!base_res)
>  		goto out4;
>

and then running:

    while true; do
        modprobe lp & modprobe parport_pc
	wait
	rmmod lp parport_pc
    done

for a few seconds.

In the long term I think port registration should be changed to put
the call to device_add() inside parport_announce_port(), but since the
latter currently cannot fail this will require changing all port
drivers.

For now, add a flag to indicate whether a port has been "announced"
and only try to attach client drivers to ports when the flag is set.

Fixes: 6fa45a2268 ("parport: add device-model to parport subsystem")
Closes: https://bugs.debian.org/1130365
Closes: https://lore.kernel.org/all/6ba903ad-9897-42bb-8c2d-337385cc3746@molgen.mpg.de/
Cc: stable <stable@kernel.org>
Signed-off-by: Ben Hutchings <benh@debian.org>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://patch.msgid.link/afo6uBv68GDevbMD@decadent.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 12:19:02 +02:00
Guangshuo Li
f74c8696f1 uio: uio_pci_generic_sva: fix double free of devm_kzalloc() memory
uio_pci_sva allocates struct uio_pci_sva_dev with devm_kzalloc() in
probe(), but then calls kfree(udev) both on the probe() error path
(label out_free) and again in remove().

Because devm_kzalloc() allocations are devres-managed and are freed
automatically when the device is detached (including after a failing
probe() and during driver unbind), the explicit kfree() can lead to a
double free.

If probe() fails after devm_kzalloc(), the error path frees udev and
devres cleanup will free it again when the core unwinds the partially
bound device. On normal driver removal, remove() frees udev and devres
will free it again when the device is detached.

This issue was identified by a static analysis tool I developed and
confirmed by manual review. Fix by removing the manual kfree() calls
and dropping the now-unused label.

Fixes: 3397c3cd85 ("uio: Add SVA support for PCI devices via uio_pci_generic_sva.c")
Cc: stable <stable@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Link: https://patch.msgid.link/20260505150256.614071-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 12:19:02 +02:00
Zeng Heng
c2ff4764e0 arm64: tlb: Flush walk cache when unsharing PMD tables
When huge_pmd_unshare() is called to unshare a PMD table, the
tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true
but the aarch64 tlb_flush() only checked tlb->freed_tables to
determine whether to use TLBF_NONE (vae1is, invalidates walk
cache) or TLBF_NOWALKCACHE (vale1is, leaf-only).

This caused the stale PMD page table entry to remain in the walk cache
after unshare, potentially leading to incorrect page table walks.

Fix by including unshared_tables in the check, so that when
unsharing tables, TLBF_NONE is used and the walk cache is properly
invalidated.

Here is the detailed distinction between vae1is and vale1is:

| Instruction Combination  | Actual Invalidation Scope                         |
| ------------------------ | --------------------------------------------------|
| `VAE1IS`  + TTL=`0`      | All entries at all levels (full invalidation)     |
| `VAE1IS`  + TTL=`2` (L2) | Non-leaf at Level 0/1 + leaf at Level 2           |
| `VALE1IS` + TTL=`0`      | Leaf entries at all levels (non-leaf not cleared) |
| `VALE1IS` + TTL=`2` (L2) | Leaf entry at Level 2 only                        |

Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Fixes: 8ce720d5bd ("mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather")
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-05-22 11:13:51 +01:00
Mike Rapoport (Microsoft)
3fb2d124b6
init: do_mounts: use kmalloc() for allocations of temporary buffers
Several places in init/do_mounts.c allocate temporary buffers for
filesystem names or options using __get_free_page() or alloc_page().

Usage of alloc_page() APIs is not required there and only creates
unnecessary noise with castings or conversion from struct page to void *.

kmalloc() is a better API for these uses and it also provides better
scalability and more debugging possibilities.

Replace use of __get_free_page() and alloc_page() with kmalloc().

While on it, add a check for -ENOMEM condition in mount_root_generic().

Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260520-init-v1-1-aaf2ebac5ad9@kernel.org
Reviewed-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-22 12:12:20 +02:00
Christian Brauner
de5fefadef
Merge patch series "writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()"
Baokun Li <libaokun@linux.alibaba.com> says:

When a container exits, a race between cgroup_writeback_umount() and
inode_switch_wbs() / cleanup_offline_cgwb() can trigger
"VFS: Busy inodes after unmount" followed by a use-after-free on
percpu counters.

There is a window between inode_prepare_wbs_switch() returning true
(having passed the SB_ACTIVE check and grabbed the inode) and the
subsequent wb_queue_isw() call.  If cgroup_writeback_umount() observes
the global isw_nr_in_flight counter as non-zero but flush_workqueue()
finds nothing queued, it returns early -- leaving a held inode
reference that blocks evict_inodes() and a later iput() that hits
freed percpu counters.

Patch 1 closes the race by extending the RCU read-side critical
section to cover the window from inode_prepare_wbs_switch() through
wb_queue_isw(), and adding synchronize_rcu() in the umount path so
that all in-flight switchers complete queueing before
flush_workqueue() runs.  rcu_barrier() is intentionally retained so
the same hunk applies cleanly to stable trees that still queue
switches via queue_rcu_work().

Patch 2 removes the now-dead rcu_barrier() that was left over from
the queue_rcu_work() era (replaced by plain queue_work() in commit
e1b849cfa6 "writeback: Avoid contention on wb->list_lock when
switching inodes").  This is mainline-only.

Patch 3 replaces the global synchronize_rcu()/flush_workqueue() pair
with a per-sb counter (s_isw_nr_in_flight) plus three small helpers
(cgroup_writeback_pin / cgroup_writeback_unpin /
cgroup_writeback_drain), eliminating the global serialization
penalty.  This also reverts the RCU extension from patch 1 since the
per-sb counter makes it unnecessary.

Performance
-----------

Measured on a 16 vCPU QEMU guest, all kernels share the same .config.
Background load: 4 ext4 superblocks each running

  while :; do
      mkdir /sys/fs/cgroup/<tag>-tmp$N
      ( echo $BASHPID > <tag>-tmp$N/cgroup.procs
        dd if=/dev/zero of=$mp/burner bs=4k count=256 conv=notrunc \
       oflag=sync)
      rmdir /sys/fs/cgroup/<tag>-tmp$N
  done

This drives both inode_switch_wbs() (different cgroups writing the
same inode) and cleanup_offline_cgwb() (dying memcgs), keeping the
global isw_nr_in_flight non-zero throughout the run.  Latencies are
wall-clock around umount(8) on a separate target sb; only the target
sb's umount is measured.

Four kernels are compared at each step of the series:

  base       pre-fix mainline
  +race      base + patch 1 (race fix, keeps rcu_barrier)
  +rmbarrier +race + patch 2 (drop rcu_barrier)
  +persb     +rmbarrier + patch 3 (per-sb counter)

Target sb runs its own cgwb churn:

                p50      p95      p99      max
  base         99.7 ms 112.9 ms 112.9 ms 127.2 ms
  +race       110.2 ms 153.8 ms 153.8 ms 160.4 ms
  +rmbarrier   67.6 ms  88.3 ms  88.3 ms  96.8 ms
  +persb        7.9 ms  10.0 ms  10.0 ms  10.1 ms

Idle target umount under cross-sb cgwb-switch pressure:

                p50      p95      p99      max
  base         92.0 ms 123.5 ms 136.5 ms 141.3 ms
  +race       118.8 ms 154.6 ms 164.7 ms 165.3 ms
  +rmbarrier   62.7 ms  95.4 ms 108.1 ms 108.6 ms
  +persb        5.3 ms   6.9 ms   7.4 ms   7.4 ms

8 concurrent umounts of idle sbs under the same pressure:

                p50      p95      p99      max
  base        137.5 ms 166.9 ms 166.9 ms 171.3 ms
  +race       162.2 ms 183.9 ms 183.9 ms 217.0 ms
  +rmbarrier   61.3 ms  99.5 ms  99.5 ms 113.7 ms
  +persb        8.1 ms   9.1 ms   9.1 ms   9.5 ms

A no-pressure baseline run (no background load) measures ~5 ms p50
across all four kernels, validating that the methodology has no
systematic bias.

In-kernel cgroup_writeback_umount() cumulative cost across the same
run (bpftrace, ~340 calls covering all four scenarios):

                                cgroup_writeback_umount() time
  base                          21240 ms total  (~62 ms / call)
  +race      (rcu_barrier+sync) 24966 ms total  (~73 ms / call)
  +rmbarrier (synchronize_rcu)  12371 ms total  (~36 ms / call)
  +persb     (per-sb counter)    1.37 ms total  ( ~4 us / call)

Under +persb the wait_var_event() condition is true on entry
whenever the target sb has nothing in flight, so synchronize_rcu()
and flush_workqueue() are never called on this path.

Notes:

  - Patch 1 adds ~10-27 ms p50 over base by introducing
    synchronize_rcu().  This is the cost of closing the race
    correctly and is paid by stable backports as well.
  - Patch 2 ("drop rcu_barrier()") was expected to be a pure cleanup
    on mainline, but actually removes a real wait: rcu_barrier()
    drains call_rcu() callbacks from *all* subsystems, and the
    cgroup teardown path keeps that pipeline busy under this
    workload.  Removing it cuts ~43-101 ms p50 on top of patch 1.
  - Patch 3 (per-sb counter) replaces the global wait entirely; the
    target sb no longer waits for activity on unrelated sbs,
    recovering near-baseline latency in all three scenarios.

* patches from https://patch.msgid.link/20260521095016.2791354-1-libaokun@linux.alibaba.com:
  writeback: use a per-sb counter to drain inode wb switches at umount
  writeback: drop now-unnecessary rcu_barrier() in cgroup_writeback_umount()
  writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()

Link: https://patch.msgid.link/20260521095016.2791354-1-libaokun@linux.alibaba.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-22 12:06:42 +02:00
Baokun Li
31c1d19ead
writeback: use a per-sb counter to drain inode wb switches at umount
Tracking in-flight inode wb switches with a single global counter
(isw_nr_in_flight) plus a synchronize_rcu() based wait in
cgroup_writeback_umount() forces every umount to take a global hit
whenever any other superblock on the system has wb switches in flight,
even if the superblock being unmounted has none of its own.

Replace the global synchronize_rcu()/flush_workqueue() pair with a
per-sb counter, s_isw_nr_in_flight, plus three small helpers:

  - cgroup_writeback_pin(sb)   - increment counter
  - cgroup_writeback_unpin(sb) - decrement and wake drainer if last
  - cgroup_writeback_drain(sb) - wait for counter to reach zero

The wiring is:

  - inode_prepare_wbs_switch() pins before checking SB_ACTIVE and
    grabbing the inode; failure paths unpin before returning.  A
    lockless SB_ACTIVE check at the top of the function lets us skip
    the atomic_inc/smp_mb dance once SB_ACTIVE has been cleared (it
    is monotonic and never set back).
  - process_inode_switch_wbs() unpins after the matching iput().
  - cgroup_writeback_umount() drains the per-sb counter via
    wait_var_event().

The smp_mb() pair between inode_prepare_wbs_switch() and
cgroup_writeback_umount() keeps the SB_ACTIVE / counter ordering:
either the umounter sees a non-zero counter and waits, or the
switcher sees SB_ACTIVE cleared and aborts before grabbing the
inode.

The global isw_nr_in_flight is left in place, since it is still used
to throttle in-flight switches via WB_FRN_MAX_IN_FLIGHT.

The rcu_read_lock() extension in inode_switch_wbs() and
cleanup_offline_cgwb() that the race fix added is no longer needed
and is reverted; the synchronize_rcu() that the race fix added to
cgroup_writeback_umount() is dropped as well.

The following numbers were measured on a 16 vCPU QEMU guest with 4
background superblocks each churning "create memcg -> write 1 MiB ->
rmdir memcg" to keep the global isw_nr_in_flight non-zero.  Latencies
are wall-clock around umount(8); only the target sb's umount is
measured.

Target sb runs its own cgwb churn:

                              p50      p95      p99      max
  global synchronize_rcu()   67.6 ms  88.3 ms  88.3 ms  96.8 ms
  per-sb counter (this)       7.9 ms  10.0 ms  10.0 ms  10.1 ms

Idle target umount latency under cross-sb cgwb-switch pressure:

                              p50      p95      p99      max
  global synchronize_rcu()   62.7 ms  95.4 ms 108.1 ms 108.6 ms
  per-sb counter (this)       5.3 ms   6.9 ms   7.4 ms   7.4 ms
  no-pressure baseline        4.9 ms   5.9 ms   6.3 ms   6.7 ms

8 concurrent umounts of idle sbs under the same pressure:

                              p50      p95      max
  global synchronize_rcu()   61.3 ms  99.5 ms 113.7 ms
  per-sb counter (this)       8.1 ms   9.1 ms   9.5 ms

In-kernel cgroup_writeback_umount() time across the same run
(bpftrace, ~340 calls covering all scenarios):

  global synchronize_rcu()    12371 ms total (~36 ms / call)
  per-sb counter (this)        1.37 ms total ( ~4 us / call)

Suggested-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/177910456953.488929.2169908940676707307.b4-review@b4
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260521095016.2791354-4-libaokun@linux.alibaba.com
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-22 12:06:35 +02:00
Baokun Li
e90a6d668e
writeback: drop now-unnecessary rcu_barrier() in cgroup_writeback_umount()
Commit e1b849cfa6 ("writeback: Avoid contention on wb->list_lock when
switching inodes") replaced the queue_rcu_work() based scheduling of
inode wb switches with a plain queue_work().  Since then no switcher
goes through call_rcu(), so rcu_barrier() in cgroup_writeback_umount()
has no callbacks of its own to wait for.  It still drains unrelated
call_rcu() callbacks from other subsystems on busy systems, which
incidentally slows umount down; drop it.

Fixes: e1b849cfa6 ("writeback: Avoid contention on wb->list_lock when switching inodes")
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260521095016.2791354-3-libaokun@linux.alibaba.com
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-22 12:06:35 +02:00
Baokun Li
cba38ec4cb
writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()
When a container exits, the following BUG_ON() is occasionally triggered:

==================================================================
 VFS: Busy inodes after unmount of sdb (ext4)
 ------------[ cut here ]------------
 kernel BUG at fs/super.c:695!
 CPU: 3 PID: 6 Comm: containerd-shim Tainted: G OE K 6.6 #1
 pstate: 63400009 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
 pc : generic_shutdown_super+0xf0/0x100
 lr : generic_shutdown_super+0xf0/0x100
 Call trace:
  generic_shutdown_super+0xf0/0x100
  kill_block_super+0x20/0x48
  ext4_kill_sb+0x28/0x60
  deactivate_locked_super+0x54/0x130
  deactivate_super+0x84/0xa0
  cleanup_mnt+0xa4/0x140
  __cleanup_mnt+0x18/0x28
  task_work_run+0x78/0xe0
  do_notify_resume+0x204/0x240
==================================================================

The root cause is a race between cgroup_writeback_umount() and
inode_switch_wbs()/cleanup_offline_cgwb(). There is a window between
inode_prepare_wbs_switch() returning true and the subsequent
wb_queue_isw() call. Following is the process that triggers the issue:

      CPU A (umount)           |          CPU B (writeback)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                 inode_switch_wbs/cleanup_offline_cgwb
                                  atomic_inc(&isw_nr_in_flight)
                                  inode_prepare_wbs_switch
                                   -> passes SB_ACTIVE check
                                   __iget(inode)
 generic_shutdown_super
  sb->s_flags &= ~SB_ACTIVE
  cgroup_writeback_umount(sb)
   smp_mb()
   atomic_read(&isw_nr_in_flight)
   rcu_barrier()
    -> no pending RCU callbacks
   flush_workqueue(isw_wq)
    -> nothing queued, returns
  evict_inodes(sb)
   -> Inode skipped as isw still holds a ref.
  sop->put_super(sb)
   /* destroys percpu counters */
  -> VFS: Busy inodes after unmount!
                                  wb_queue_isw()
                                   queue_work(isw_wq, ...)
                                  /* later in work function */
                                  inode_switch_wbs_work_fn
                                   process_inode_switch_wbs
                                    iput() -> evict
                                     percpu_counter_dec() // UAF!

Fix this by extending the RCU read-side critical section in
inode_switch_wbs() and cleanup_offline_cgwb() to cover from
inode_prepare_wbs_switch() through wb_queue_isw().  Since there is
no sleep in this window, rcu_read_lock() can be used.  Then add a
synchronize_rcu() in cgroup_writeback_umount() before the existing
rcu_barrier(), so that all in-flight switchers that have passed the
SB_ACTIVE check have completed queue_work() before flush_workqueue()
is called.

The existing rcu_barrier() is intentionally retained so this fix can
be backported unchanged to stable kernels (5.10.y, 6.6.y, ...) that
still queue switches via queue_rcu_work(). It is a no-op on current
mainline (since commit e1b849cfa6 ("writeback: Avoid contention on
wb->list_lock when switching inodes")) and is removed in a follow-up
patch.

Fixes: a1a0e23e49 ("writeback: flush inode cgroup wb switches instead of pinning super_block")
Cc: stable@vger.kernel.org
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/all/mxnjq2l6guusfchvauxr3v7c4bwjasybxlleqbbh4efloeqspz@iqylk76ohufz
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260521095016.2791354-2-libaokun@linux.alibaba.com
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-05-22 12:06:35 +02:00
Matthew Maurer
f6d8fea9e3 rust_binder: Avoid holding lock when dropping delivered_death
In 6c37bebd8c, we switched to looping over the list and dropping each
individual node, ostensibly without the lock held in the loop body.

If the kernel were using Rust Edition 2024, the comment would be
accurate, and the lock would not be held across the drop. However, the
kernel is currently using 2021, so tail expression lifetime extension
results in the lock being held across the drop. Explicitly binding the
expression result to a variable makes the lockguard no longer part of a
tail expression, causing the lock to be dropped before entering the loop
body.

This was detected via `CONFIG_PROVE_LOCKING` identifying an invalid wait
context at the drop site.

Reported-by: David Stevens <stevensd@google.com>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Cc: stable <stable@kernel.org>
Fixes: 6c37bebd8c ("rust_binder: avoid mem::take on delivered_deaths")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://patch.msgid.link/20260403-lockhold-v1-1-c332b56cd8ae@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:55:48 +02:00
Alice Ryhl
4c19719eb8 rust_binder: avoid calling pending_oneway_finished() on TF_UPDATE_TXN
When an outdated transaction is removed from `oneway_todo` due to
`TF_UPDATE_TXN`, its `Allocation` is dropped. The current implementation
of `Allocation::drop` calls `pending_oneway_finished()`, assuming the
transaction was executed. This leads to premature execution of the next
queued one-way transaction.

Fix this by taking the `oneway_node` from the `Allocation` of the
outdated transaction before it is dropped. This prevents
`Allocation::drop` from signaling completion.

We do not call `take_oneway_node()` from `Transaction::cancel` because
it's actually correct to call `pending_oneway_finished()` on cancel if
the transaction did not come from `oneway_todo`. This ensures that if
`BINDER_THREAD_EXIT` is invoked and cancels a oneway transaction, then
the next transaction is taken from `oneway_todo`.

This bug does not lead to any issues in the kernel, but may lead to
Binder delivering transactions to userspace earlier than userspace
expected to receive them.

Cc: stable <stable@kernel.org>
Fixes: eafedbc7c0 ("rust_binder: add Rust Binder driver")
Assisted-by: Antigravity:gemini
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://patch.msgid.link/20260414-tf-update-txn-fix-v1-1-d2b83303acc9@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:55:33 +02:00
Maciej W. Rozycki
e4240d8845 serial: dz: Enable modular build
Enable modular build since the driver now has a proper module_exit()
handler.  There's nothing specific to DZ hardware to prevent driver
unloading and reloading from working.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062331420.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:34 +02:00
Maciej W. Rozycki
7cac59d08a serial: zs: Convert to use a platform device
Prevent a crash from happening as the first serial port is initialised:

  Console: switching to mono frame buffer device 160x64
  fb0: PMAG-AA frame buffer device at tc0
  DECstation Z85C30 serial driver version 0.10
  CPU 0 Unable to handle kernel paging request at virtual address 0000002c, epc == 803ab00c, ra == 803aafe0
  Oops[#1]:
  CPU: 0 PID: 1 Comm: swapper Not tainted 6.4.0-rc3-00031-g84a9582fd203-dirty #57
  $ 0   : 00000000 10012c00 803aaeb0 00000000
  $ 4   : 80e12f60 80e12f50 80e12f58 81000030
  $ 8   : 00000000 805ff37c 00000000 33433538
  $12   : 65732030 00000006 80c2915d 6c616972
  $16   : 80e12f00 807b7630 00000000 00000000
  $20   : 00000004 00000348 000001a0 807623b8
  $24   : 00000018 00000000
  $28   : 80c24000 80c25d60 8078b148 803aafe0
  Hi    : 00000000
  Lo    : 00000000
  epc   : 803ab00c serial_base_ctrl_add+0x78/0xf4
  ra    : 803aafe0 serial_base_ctrl_add+0x4c/0xf4
  Status: 10012c03	KERNEL EXL IE
  Cause : 00000008 (ExcCode 02)
  BadVA : 0000002c
  PrId  : 00000440 (R4400SC)
  Modules linked in:
  Process swapper (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000)
  Stack : 80760000 00000cc0 00400044 00400040 803aa02c 80d61ab8 00000000 807b7630
          80760000 807623b8 807b7628 803aa644 80386998 00000000 80e17780 80220f68
          80e17780 80d61ab8 80c17d80 80e17780 80e17780 8063c798 80e17780 80383fa0
          00000010 80e17780 00000000 80386998 807a0000 00000000 00400040 8038f848
          807623b8 80d61ab8 00000004 80e17780 00000000 803a68e4 80c25e2c 803bb884
          ...
  Call Trace:
  [<803ab00c>] serial_base_ctrl_add+0x78/0xf4
  [<803aa644>] serial_core_register_port+0x174/0x69c
  [<8077e9ac>] zs_init+0xc8/0xfc
  [<800404d4>] do_one_initcall+0x40/0x2ac
  [<8076cecc>] kernel_init_freeable+0x1e4/0x270
  [<80605bec>] kernel_init+0x20/0x108
  [<800431e8>] ret_from_kernel_thread+0x14/0x1c

  Code: 2442aeb0  ae120024  ae0200d0 <8c67002c> 50e00001  8c670000  3c06806e  3c05806e  afb30010

  ---[ end trace 0000000000000000 ]---

(report at the offending commit) -- where a pointer is dereferenced that
has been derived from a null pointer to the port's parent device.

Since no device is available with legacy probing and it's not anymore a
preferable way to discover devices anyway, switch the driver to using a
platform device and use it as the port's parent device.  Update resource
handling accordingly and only request the actual span of addresses used
within the slot, which will have had its resource already requested by
generic platform device code.

Use platform_driver_probe() not just because SCC devices are fixed with
solder on board and not straightforward to remove, but foremost because
the associated TTY's major device number is the same as used by the dz
driver and the first driver to claim it will prevent the other one from
using it.  Either one DZ device or some SCC devices will be present in a
given system but never both at a time, and therefore we want the major
device number to be claimed by the first driver to actually successfully
bind to its device and platform_driver_probe() is a way to fulfil that.

An unfortunate consequence of the switch to a platform device is we now
hand the console over from the bootconsole much later in the bootstrap.
The firmware console handler appears good enough though to work so late
and in particular with interrupts enabled.

Since there is one way only remaining to reach zs_reset() now, remove
the port initialisation marker as no longer needed and go through the
channel reset unconditionally.

Fixes: 84a9582fd2 ("serial: core: Start managing serial controllers to enable runtime PM")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062328480.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:34 +02:00
Maciej W. Rozycki
5d7a49d60b serial: dz: Convert to use a platform device
Prevent a crash from happening as the first serial port is initialised:

  Console: switching to colour frame buffer device 160x64
  tgafb: SFB+ detected, rev=0x02
  fb0: Digital ZLX-E1 frame buffer device at 0x1e000000
  DECstation DZ serial driver version 1.04
  CPU 0 Unable to handle kernel paging request at virtual address 000000bc, epc == 8048b3a4, ra == 80470a78
  Oops[#1]:
  CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.19.0-dirty #35 NONE
  $ 0   : 00000000 1000ac00 00000004 804707ac
  $ 4   : 00000000 80e20850 80e20858 81000030
  $ 8   : 00000000 8072c81c 00000008 fefefeff
  $12   : 6c616972 00000006 80c5917f 69726420
  $16   : 80e20800 00000000 808f8968 80e20800
  $20   : 00000000 807f5a90 808b0094 808d3bc8
  $24   : 00000018 80479030
  $28   : 80c2e000 80c2fd70 00000069 80470a78
  Hi    : 00000004
  Lo    : 00000000
  epc   : 8048b3a4 __dev_fwnode+0x0/0xc
  ra    : 80470a78 serial_base_ctrl_add+0xa0/0x168
  Status: 1000ac04	IEp
  Cause : 30000008 (ExcCode 02)
  BadVA : 000000bc
  PrId  : 00000220 (R3000)
  Modules linked in:
  Process swapper/0 (pid: 1, threadinfo=(ptrval), task=(ptrval), tls=00000000)
  Stack : 00400044 00400040 8046f4cc 00000000 808a6148 808a0000 808f8968 8086983c
          808e0000 8046fc84 1000ac01 00000028 80e20700 802ba3f8 80e20700 80d34a94
          80c1b900 80e20700 80e20700 80e20700 80e20700 80444650 00000000 00000000
          00000000 807f5a90 808b0094 80447080 00400040 808e0000 80d34a94 808a6148
          80d34a94 00000004 80e20700 00000000 8076974c 80469810 80c2fe3c 1000ac01
          ...
  Call Trace:
  [<8048b3a4>] __dev_fwnode+0x0/0xc
  [<80470a78>] serial_base_ctrl_add+0xa0/0x168
  [<8046fc84>] serial_core_register_port+0x1c8/0x974
  [<808c6af0>] dz_init+0x74/0xc8
  [<800470e0>] do_one_initcall+0x44/0x2d4
  [<808b111c>] kernel_init_freeable+0x258/0x308
  [<8072e434>] kernel_init+0x20/0x114
  [<80049cd0>] ret_from_kernel_thread+0x14/0x1c

  Code: 27bd0018  03e00008  2402ffea <8c8200bc> 03e00008  00000000  27bdffc0  afbe0038  afb30024

  ---[ end trace 0000000000000000 ]---

-- where a pointer is dereferenced that has been derived from a null
pointer to the port's parent device.

Since no device is available with legacy probing and it's not anymore a
preferable way to discover devices anyway, switch the driver to using a
platform device and use it as the port's parent device.  Update resource
handling accordingly and only request the actual span of addresses used
within the slot, which will have had its resource already requested by
generic platform device code.

Use platform_driver_probe() not just because the DZ device is fixed with
solder on board and not straightforward to remove, but foremost because
the associated TTY's major device number is the same as used by the zs
driver and the first driver to claim it will prevent the other one from
using it.  Either one DZ device or some SCC devices will be present in a
given system but never both at a time, and therefore we want the major
device number to be claimed by the first driver to actually successfully
bind to its device and platform_driver_probe() is a way to fulfil that.

An unfortunate consequence of the switch to a platform device is we now
hand the console over from the bootconsole much later in the bootstrap.
The firmware console handler appears good enough though to work so late
and in particular with interrupts enabled.

Conversely only starting the console port so late lets the reset code
fully utilise our delay handlers, so switch from udelay() to fsleep()
for transmitter draining so as to avoid busy-waiting for an excessive
amount of time.

Fixes: 84a9582fd2 ("serial: core: Start managing serial controllers to enable runtime PM")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # needs to use .remove_new for <= 6.10
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062326540.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:34 +02:00
Maciej W. Rozycki
8572955630 serial: zs: Switch to using channel reset
Switch the driver to using the channel reset rather than hardware reset,
simplifying handling by removing an interference between channels that
causes the other channel to become uninitialised afterwards.

There is little difference between the two kinds of reset in terms of
register settings that result, and we initialise the whole register set
right away anyway.  However this prevents a hang from happening should
the console output handler in the firmware try to access the other port
whose transmitter has been disabled and line parameters messed up.

For example this will happen if the keyboard port (port A) is chosen for
the system console, unusually but not insanely for a headless system, as
the port is wired to a standard DA-15 connector and an adapter can be
easily made.  Or with the next change in place this would happen for the
regular console port (port B), since the keyboard port (port A) will be
initialised first.

Just remove the unnecessary complication then, a channel reset is good
enough.  We still need the initialisation marker, now per channel rather
than per SCC, as for the console port zs_reset() will be called twice:
once early on via zs_serial_console_init() for the console setup only,
and then again via zs_config_port() as the port is associated with a TTY
device.

Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.23+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062323430.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:34 +02:00
Maciej W. Rozycki
6c05cf72e1 serial: zs: Fix bootconsole handover lockup
Calling zs_reset() in the course of setting up the serial device causes
line parameters to be reset and the transmitter disabled.  We've been
lucky in that no message is usually produced to the kernel log between
this call and the later call to uart_set_options() in the course of
console setup done by zs_serial_console_init(), or the system would hang
as the console output handler in the firmware tried to access a port the
transmitter of which has been disabled and line parameters messed up.

This will change with the next change to the driver, so fix zs_reset()
such that line parameters are set for 9600n8 console operation as with
the system firmware and the transmitter re-enabled after reset.  This
also means zs_pm() serves no purpose anymore, so drop it.

Fixes: 8b4a40809e ("zs: move to the serial subsystem")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.23+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062308040.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:34 +02:00
Maciej W. Rozycki
7f127b2208 serial: dz: Fix bootconsole handover lockup
Calling dz_reset() in the course of setting up the serial device causes
line parameters to be reset and the transmitter disabled.  We've been
lucky in that no message is usually produced to the kernel log between
this call and the later call to uart_set_options() in the course of
console setup done by dz_serial_console_init(), or the system would hang
as the console output handler in the firmware tried to access a port the
transmitter of which has been disabled and line parameters messed up.

This will change with the next change to the driver, so fix dz_reset()
such that line parameters are set for 9600n8 console operation as with
the system firmware and the transmitter re-enabled after reset.  This
also means dz_pm() serves no purpose anymore, so drop it.

Fixes: e6ee512f5a ("dz.c: Resource management")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.25+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062302010.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:34 +02:00
Maciej W. Rozycki
ca904f4b42 serial: dz: Fix bootconsole message clobbering at chip reset
In the DZ interface as implemented by the DC7085 gate array the serial
transmitters are double buffered, meaning that at the time a transmitter
is ready to accept the next character there is one in the transmit shift
register still being sent to the line.  Issuing a master clear at this
time causes this character to be lost, so wait an extra amount of time
sufficient for the transmit shift register to drain at 9600bps, which is
the baud rate setting used by the firmware console.

Mind the specified 1.4us TRDY recovery time in the course and continue
using iob() as the completion barrier, since the platforms involved use
a write buffer that can delay and combine writes, and reorder them with
respect to reads regardless of the MMIO locations accessed and we still
lack a platform-independent handler for that.

When called from dz_serial_console_init() this is too early for fsleep()
to work and even before lpj has been calculated and therefore the delay
is actually not sufficient for the transmitter to drain and is merely a
placeholder now.  This will be addressed in a follow-up change.

Fixes: e6ee512f5a ("dz.c: Resource management")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.25+
Link: https://patch.msgid.link/alpine.DEB.2.21.2605062259080.46195@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:52:33 +02:00
Jacques Nilo
2e21172395 serial: 8250_dw: dispatch SysRq character in dw8250_handle_irq()
dw8250_handle_irq() calls serial8250_handle_irq_locked() with the port
lock held via guard(uart_port_lock_irqsave). The guard destructor is
plain uart_port_unlock_irqrestore(), so a SysRq character captured into
port->sysrq_ch by uart_prepare_sysrq_char() is dropped without ever
being dispatched to handle_sysrq().

This is the same regression pattern as in serial8250_handle_irq(),
introduced when 883c5a2bc9 ("serial: 8250_dw: Rework
dw8250_handle_irq() locking and IIR handling") moved the function to
the guard()-based locking scheme without using the sysrq-aware unlock
helper.

Switch to guard(uart_port_lock_check_sysrq_irqsave) so that captured
sysrq_ch is dispatched on scope exit, matching the fix in
serial8250_handle_irq().

Fixes: 883c5a2bc9 ("serial: 8250_dw: Rework dw8250_handle_irq() locking and IIR handling")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/ed56fcaf4af24e4ed011a7bce206e0182acb761c.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:51:35 +02:00
Jacques Nilo
71f42b2149 serial: 8250: dispatch SysRq character in serial8250_handle_irq()
serial8250_handle_irq() captures a SysRq character into port->sysrq_ch
inside serial8250_handle_irq_locked() via uart_prepare_sysrq_char()
(reached from serial8250_read_char()). Dispatch of that captured
character to handle_sysrq() is expected to happen at port-unlock time,
through uart_unlock_and_check_sysrq[_irqrestore]().

After commit 8324a54f60 ("serial: 8250: Add
serial8250_handle_irq_locked()") the function was reduced to a wrapper
that takes the port lock via guard(uart_port_lock_irqsave) whose
destructor is plain uart_port_unlock_irqrestore(). The sysrq-aware
unlock helper is no longer called, so port->sysrq_ch is captured but
never dispatched: BREAK + SysRq key is consumed silently.

This was the very condition Johan Hovold's 853a9ae29e ("serial:
8250: fix handle_irq locking", 2021) introduced
uart_unlock_and_check_sysrq_irqrestore() to address.

Switch to the new guard(uart_port_lock_check_sysrq_irqsave), whose
destructor is the sysrq-aware unlock helper, restoring the pre-split
behaviour. Update the Context: comment on serial8250_handle_irq_locked()
so future HW-specific 8250 wrappers know to use the same guard or the
explicit sysrq-aware unlock.

Verified on RTL8196E with CONFIG_MAGIC_SYSRQ_SERIAL=y: BREAK + 'h' on
the console UART produces the SysRq help dump in dmesg and the brk
counter in /proc/tty/driver/serial increments correctly.

Fixes: 8324a54f60 ("serial: 8250: Add serial8250_handle_irq_locked()")
Cc: stable@vger.kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Link: https://patch.msgid.link/52692ae6c3501f7940347cef364ad7fcacaab7e5.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:51:35 +02:00
Jacques Nilo
c3cce2e67b serial: core: introduce guard(uart_port_lock_check_sysrq_irqsave)
uart_handle_break() and uart_prepare_sysrq_char() (in
include/linux/serial_core.h) capture a SysRq character into
port->sysrq_ch while the port lock is held and rely on the unlock
helper -- uart_unlock_and_check_sysrq_irqrestore() -- to dispatch the
captured character to handle_sysrq() on scope exit.

The existing guard(uart_port_lock_irqsave) cannot be used by IRQ
handlers that process RX, because its destructor calls plain
uart_port_unlock_irqrestore() and silently drops port->sysrq_ch.

Add a dedicated guard(uart_port_lock_check_sysrq_irqsave) variant
whose destructor is the sysrq-aware unlock helper. The lock side is
identical to uart_port_lock_irqsave -- only the unlock-time behaviour
differs. Callers that may capture SysRq characters must use
guard(uart_port_lock_check_sysrq_irqsave); the existing
guard(uart_port_lock_irqsave) keeps its current plain-unlock semantics
for the many callers that do not process RX.

The new macro is placed after the CONFIG_MAGIC_SYSRQ_SERIAL block so
both definitions of uart_unlock_and_check_sysrq_irqrestore() (sysrq
enabled and disabled) are visible at expansion time. When
CONFIG_MAGIC_SYSRQ_SERIAL=n the destructor degenerates to plain
uart_port_unlock_irqrestore(), so there is no overhead.

No functional change on its own; users are converted in the following
patches.

Cc: stable@vger.kernel.org
Signed-off-by: Jacques Nilo <jnilo@free.fr>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/3849af4bc55d5d2a424fa850844e94d641b2f8a6.1778675349.git.jnilo@free.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:51:35 +02:00
Tudor Ambarus
a3bb136bff tty: serial: samsung: Remove redundant port lock acquisition in rx helpers
Sashiko identified a deadlock when the console flow is engaged [1].

When console flow control is enabled (UPF_CONS_FLOW),
s3c24xx_serial_stop_tx() calls s3c24xx_serial_rx_enable() and
s3c24xx_serial_start_tx() calls s3c24xx_serial_rx_disable().

The serial core framework invokes the .stop_tx() and .start_tx()
callbacks with the port->lock spinlock already held. Furthermore, all
internal driver paths that invoke stop_tx (such as the DMA TX
completion handler s3c24xx_serial_tx_dma_complete() or the PIO TX IRQ
handler s3c24xx_serial_tx_irq()) also acquire port->lock prior to
calling it. (Note that s3c24xx_serial_start_tx() is only invoked by the
serial core).

However, s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable()
unconditionally attempt to acquire port->lock again using
uart_port_lock_irqsave(). Since spinlocks are not recursive, this
causes a deadlock on the same CPU when console flow control is engaged.

Remove the redundant lock acquisition from both rx helper functions.

Cc: stable <stable@kernel.org>
Fixes: b497549a03 ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers")
Reported-by: John Ogness <john.ogness@linutronix.de>
Closes: https://sashiko.dev/#/patchset/20260506121606.5805-1-john.ogness%40linutronix.de [1]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20260515-samsung-tty-flow-control-deadlock-v1-1-93255edbc9bc@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:48:38 +02:00
Myeonghun Pak
ea66be25f0 serial: altera_jtaguart: handle uart_add_one_port() failures
altera_jtaguart_probe() maps the register window before registering the
UART port, but it ignores failures from uart_add_one_port(). If port
registration fails, probe still returns success and the mapping remains
live until a later remove path that is not part of probe failure cleanup.

Return the uart_add_one_port() error and unmap the register window on
that failure path.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: 5bcd601049 ("serial: Add driver for the Altera JTAG UART")
Cc: stable <stable@kernel.org>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260512065837.79528-1-mhun512@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:48:23 +02:00
Wentao Guan
5eb070769e USB: cdc-acm: Fix bit overlap and move quirk definitions to header
The VENDOR_CLASS_DATA_IFACE and ALWAYS_POLL_CTRL quirk flags added in
commit f58752ebcb ("USB: cdc-acm: Add quirks for Yoga Book 9 14IAH10
INGENIC touchscreen") were placed inside the acm_ctrl_msg() function
rather than in the header with the other quirk flags.  Then, their
values (BIT(9) and BIT(10)) collided with NO_UNION_12 which is already
BIT(9).

Move the definitions to drivers/usb/class/cdc-acm.h where they belong
and shift them to BIT(10) and BIT(11) to avoid the overlap.

Fixes: f58752ebcb ("USB: cdc-acm: Add quirks for Yoga Book 9 14IAH10 INGENIC touchscreen")
Cc: stable <stable@kernel.org>
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Link: https://patch.msgid.link/20260522091357.1301196-1-guanwentao@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:27:34 +02:00
Claudio Imbrenda
9029496abf KVM: s390: Properly reset zero bit in PGSTE
In case of memory pressure, it's possible that a guest page gets freed
and then almost immediately reused by the guest. If CMMA is enabled,
_essa_clear_cbrl() will discard all pages that are either unused or
zero. If a discarded page is reused before _essa_clear_cbrl() is called,
and the pgste.zero bit is not cleared, the page will be discarded
despite not being unused.

When calling _gmap_ptep_xchg(), always clear the pgste.zero bit. This
prevents the page from being accidentally discarded when not unused.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: a2c17f9270 ("KVM: s390: New gmap code")
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-05-22 11:25:11 +02:00
Claudio Imbrenda
a488e753de KVM: s390: vsie: Fix redundant rmap entries
The address passed to the gmap rmap was not being masked. As a
consequence several different (but functionally equivalent) rmap
entries were being created for each shadowed table.

Fix this by properly masking the address depending on the table level.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: a2c17f9270 ("KVM: s390: New gmap code")
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-05-22 11:25:11 +02:00
Claudio Imbrenda
2d505c2906 KVM: s390: vsie: Fix unshadowing logic
In some cases (i.e. under extreme memory pressure on the host),
attempting to shadow memory will result in the same memory being
unshadowed, causing a loop.

Add a PGSTE bit to distinguish between shadowed memory and shadowed DAT
tables, fix the unshadowing logic in _gmap_ptep_xchg() to prevent
unnecessary unshadowing and perform better checks.

Also fix the unshadowing logic in _gmap_crstep_xchg_atomic() which did
not unshadow properly when the large page would become unprotected.

Opportunistically add a check in gmap_protect_rmap() to make sure it
won't be called with level == TABLE_TYPE_PAGE_TABLE.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: a2c17f9270 ("KVM: s390: New gmap code")
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-05-22 11:25:10 +02:00
Claudio Imbrenda
4df4b7cdf5 KVM: s390: Fix leaking kvm_s390_mmu_cache in case of errors
Fix a memory leak that can happen if gmap_ucas_map_one() or
kvm_s390_mmu_cache_topup() return error values.

Also fix a similar issue in gmap_set_limit().

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Fixes: a2c17f9270 ("KVM: s390: New gmap code")
Reported-by: Jiaxin Fan <jiaxin.fan@ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-05-22 11:25:10 +02:00
Claudio Imbrenda
d0f2eb4493 KVM: s390: vsie: Fix memory leak when unshadowing
When performing a partial unshadowing, the rmap was being leaked.

Add the missing kfree().

Fixes: a2c17f9270 ("KVM: s390: New gmap code")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-05-22 11:25:10 +02:00
Dan Carpenter
9ea06a3fbf usb: dwc2: Fix use after free in debug code
We're not allowed to dereference "urb" after calling
usb_hcd_giveback_urb() so save the urb->status ahead of time.

Fixes: 7359d482eb ("staging: HCD files for the DWC2 driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Dan Carpenter <error27@gmail.com>
Link: https://patch.msgid.link/ag1NwBpqT4IEQcdJ@stanley.mountain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:21:07 +02:00
Xu Yang
8f6aa39265 usb: chipidea: core: convert ci_role_switch to local variable
When a system contains multiple USB controllers, the global ci_role_switch
variable may be overwritten by subsequent driver initialization code.

This can cause issues in the following cases:
 - The 2nd ci_hdrc_probe() sees ci_role_switch.fwnode as non-NULL even
   though the "usb-role-switch" property is not present for the controller.
 - When the ci_hdrc device is unbound and bound again, ci_role_switch
   fwnode will not be reassigned, and the old value will be used instead.

Convert ci_role_switch to a local variable to fix these issues.

Fixes: 05559f10ed ("usb: chipidea: add role switch class support")
Cc: stable <stable@kernel.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://patch.msgid.link/20260427075755.3611217-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:20:56 +02:00
Michael Bommarito
2796646f6d usb: gadget: f_fs: serialize DMABUF cancel against request completion
ffs_epfile_dmabuf_io_complete() calls usb_ep_free_request() on the
completed request but leaves priv->req, the back-pointer that
ffs_dmabuf_transfer() set on submission, pointing at the freed
memory.  A later FUNCTIONFS_DMABUF_DETACH ioctl or
ffs_epfile_release() on the close path still sees priv->req
non-NULL under ffs->eps_lock:

    if (priv->ep && priv->req)
            usb_ep_dequeue(priv->ep, priv->req);

so usb_ep_dequeue() is called on a freed usb_request.

On dummy_hcd the dequeue path only walks a live queue and
pointer-compares, so the freed pointer reads without faulting and
KASAN requires an explicit check at the FunctionFS call site to
surface the use-after-free.  On SG-capable in-tree UDCs the
dequeue path dereferences the supplied request immediately:

  * chipidea's ep_dequeue() does
    container_of(req, struct ci_hw_req, req) and reads
    hwreq->req.status before acquiring its own lock.
  * cdnsp's cdnsp_gadget_ep_dequeue() reads request->status first.

The narrower option of clearing priv->req via cmpxchg() in the
completion does not close the race: the completion runs without
eps_lock, so a cancel path holding eps_lock can still observe
priv->req non-NULL, race a concurrent completion that clears and
frees, and pass the freed pointer to usb_ep_dequeue().  A slightly
longer fix that moves the free into the cleanup work is needed.

Same class of lifetime race as the recent usbip-vudc timer fix [1].

Take eps_lock in the sole place that mutates priv->req from the
callback direction by moving usb_ep_free_request() out of the
completion into ffs_dmabuf_cleanup(), the existing work handler
scheduled by ffs_dmabuf_signal_done() on
ffs->io_completion_wq.  Clear priv->req there under eps_lock
before freeing, and only clear if priv->req still names our
request (a subsequent ffs_dmabuf_transfer() on the same
attachment may have queued a new one).

This keeps the existing dummy_hcd sync-dequeue invariant: the
completion callback is still invoked by the UDC without
eps_lock held (dummy_hcd drops its own lock before calling the
callback), and the callback now takes no f_fs lock at all.
Serialization against the cancel path happens in cleanup, which
runs from the workqueue with no f_fs lock held on entry.

The priv ref count protects the containing ffs_dmabuf_priv:
ffs_dmabuf_transfer() takes a ref via ffs_dmabuf_get(), cleanup
drops it via ffs_dmabuf_put(), so priv stays live for the
cleanup even after the cancel path's list_del + ffs_dmabuf_put.

The ffs_dmabuf_transfer() error path no longer frees usb_req
inline: fence->req and fence->ep are set before usb_ep_queue(),
so ffs_dmabuf_cleanup() (scheduled by the error-path
ffs_dmabuf_signal_done()) owns the free regardless of whether
the queue succeeded.

Reproduced under KASAN on both detach and close paths against
dummy_hcd with an observability hook
(kasan_check_byte(priv->req) immediately before usb_ep_dequeue)
at the two FunctionFS cancel sites to surface the stale-pointer
access; the hook is not part of this patch.  The KASAN
allocator / free stacks in the captured splats identify the
same request: alloc in dummy_alloc_request, free in
dummy_timer, fault reached from ffs_epfile_release (close) and
from the FUNCTIONFS_DMABUF_DETACH ioctl (detach).  With the
patch applied, both paths are silent under the same hook.

The bug is reached from the FunctionFS device node, which in
real deployments is owned by the privileged gadget daemon
(adbd, UMS, composite gadget services, etc.); it is not
reachable from unprivileged userspace or from a USB host on the
cable.  FunctionFS mounts default to GLOBAL_ROOT_UID, but the
filesystem supports uid=, gid=, and fmode= delegation to a
non-root gadget daemon, so on real deployments the attacker may
be a less-privileged service rather than root.

Fixes: 7b07a2a7ca ("usb: gadget: functionfs: Add DMABUF import interface")
Link: https://lore.kernel.org/all/20260417163552.807548-1-michael.bommarito@gmail.com/ [1]
Cc: stable <stable@kernel.org>
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Link: https://patch.msgid.link/20260419161227.1587668-1-michael.bommarito@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:20:43 +02:00
Michael Bommarito
4e036c10e7 usb: gadget: f_fs: copy only received bytes on short ep0 read
ffs_ep0_read() allocates its control-OUT data buffer with
kmalloc() (not kzalloc) at the Length value from the Setup
packet, then copies that full len to userspace regardless of
how many bytes were actually received:

    data = kmalloc(len, GFP_KERNEL);
    ...
    ret = __ffs_ep0_queue_wait(ffs, data, len);
    if ((ret > 0) && (copy_to_user(buf, data, len)))
            ret = -EFAULT;

__ffs_ep0_queue_wait() returns req->actual, which on a short
control OUT transfer is strictly less than len.  The
copy_to_user() call still copies len bytes, so on a short OUT
the last (len - ret) bytes of the kmalloc() buffer --
uninitialised slab residue -- are delivered to the FunctionFS
daemon.

Short ep0 OUT completions are specified USB control-transfer
behavior and are produced by in-tree UDCs:

  * dwc2 continues on req->actual < req->length for ep0 DATA OUT
    (short-not-ok is the only ep0-OUT stall path).
  * aspeed_udc ends ep0 OUT on rx_len < ep->ep.maxpacket.
  * renesas_usbf logs "ep0 short packet" and completes the
    request.
  * dwc3 stalls on short IN but not on short OUT.

A short ep0 OUT is therefore not evidence of a broken UDC; it is
a normal condition f_fs has to cope with.  The sibling gadgetfs
implementation in drivers/usb/gadget/legacy/inode.c already does
this correctly via min(len, dev->req->actual) before
copy_to_user().  This patch brings f_fs.c to the same safe
pattern rather than trimming at a defensive layer.

The bug is reached from the FunctionFS device node, which in
real deployments is owned by the privileged gadget daemon
(adbd, UMS, composite gadget services, etc.); it is not
reachable from unprivileged userspace.  Linux host stacks
normally reject short-wLength control OUTs before they reach
the gadget, so reproducing this required a build that
bypasses that host-side check.  With the bypass in place, a
1-byte payload on a 64-byte Setup produces 63 bytes of
non-canary slab residue in the daemon's read buffer.

Fix by copying only ret (actually received) bytes to
userspace.

Fixes: ddf8abd259 ("USB: f_fs: the FunctionFS driver")
Cc: stable <stable@kernel.org>
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Link: https://patch.msgid.link/20260419160359.1577270-1-michael.bommarito@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:20:30 +02:00
Seungjin Bae
7d9633528d usb: gadget: dummy_hcd: Reject hub port requests for non-existent ports
The `dummy_hub_control()` function handles USB hub class requests
to the virtual root hub. The `GetPortStatus` case returns -EPIPE for
requests with `wIndex != 1`, since the virtual root hub has only a
single port. However, the `ClearPortFeature` and `SetPortFeature`
cases lack the same check.

Fix this by extending the `wIndex != 1` rejection to both cases,
matching the existing behavior of `GetPortStatus`.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable <stable@kernel.org>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Seungjin Bae <eeodqql09@gmail.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://patch.msgid.link/20260518234314.1889396-1-eeodqql09@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:13:31 +02:00
Hang Cao
f1ecb0e563 dt-bindings: usb: Fix EIC7700 USB reset's issue
The EIC7700 USB requires a USB PHY reset operation; otherwise, the USB
will not work. The reason why the USB driver that was applied can work
properly is that the USB PHY has already been reset in ESWIN's U-Boot.

However, the proper functioning of the USB driver should not be dependent
on the bootloader. Therefore, it is necessary to incorporate the USB PHY
reset signal into the DT bindings.

This patch does not introduce any backward incompatibility since the dts
is not upstream yet. As array of reset operations are used in the driver,
no modifications to the USB controller driver are needed.

Fixes: c640a4239d ("dt-bindings: usb: Add ESWIN EIC7700 USB controller")
Cc: stable <stable@kernel.org>
Signed-off-by: Hang Cao <caohang@eswincomputing.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260415064238.1784-1-caohang@eswincomputing.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:13:19 +02:00
Michael Bommarito
d96209626a usbip: vudc: Fix use after free bug in vudc_remove due to race condition
This patch follows up Zheng Wang's 2023 report of a use-after-free in
vudc_remove(). The original thread stalled on Shuah Khan's request for
runtime testing of the unplug/unbind path. This patch supplies that
testing and keeps Zheng's original fix shape.

In vudc_probe(), v_init_timer() binds udc->tr_timer.timer to v_timer().
usbip_sockfd_store() starts the timer via v_start_timer()/v_kick_timer().
vudc_remove() can then free the containing struct vudc while the timer is
still pending or executing.

KASAN confirms the race on an unpatched x86_64 QEMU guest with
CONFIG_KASAN=y, CONFIG_USBIP_VUDC=y, CONFIG_USB_ZERO=y, and a tight loop
that repeatedly writes a socket fd to usbip_sockfd, closes the socket
pair, and unbinds/rebinds usbip-vudc.0:

  BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x8ba/0x8e0
  Write of size 8 at addr ffff888001b80740 by task trigger_and_unb/239
  Allocated by task 239:
    vudc_probe+0x4d/0xaa0
  Freed by task 239:
    kfree+0x18f/0x520
    device_release_driver_internal+0x388/0x540
    unbind_store+0xd9/0x100

This lands in the timer core rather than v_timer() itself because the
embedded timer_list is being walked after its containing struct vudc has
already been freed. The underlying lifetime bug is the same one Zheng
reported.

With v_stop_timer() called from vudc_remove() and the timer deleted
synchronously, the same harness completed 5000 bind/unbind iterations
with no KASAN report.

Fixes: b6a0ca1118 ("usbip: vudc: Add UDC specific ops")
Cc: stable <stable@kernel.org>
Reported-by: Zheng Wang <zyytlz.wz@163.com>
Closes: https://lore.kernel.org/linux-usb/20230317100954.2626573-1-zyytlz.wz@163.com/
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://patch.msgid.link/20260417163552.807548-1-michael.bommarito@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:13:06 +02:00
Rob Herring (Arm)
0b5bde9e1c dt-bindings: usb: ti,omap4-musb: Drop duplicate 'usb-phy' property constraints
The deprecated 'usb-phy' property is documented already in usb.yaml and
doesn't need a type definition here. It just needs constraints on how
many entries there are.

As this is a host controller, reference usb-hcd.yaml which then
references usb.yaml.

Fixes: 70fcdc82cf ("dt-bindings: usb: ti,omap4-musb: convert to DT schema")
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260508182556.1759173-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:12:57 +02:00
Sam Burkels
b53ebb811e usb: storage: Add quirks for PNY Elite Portable SSD
The PNY Elite Portable SSD (USB ID 154b:f009) is a sibling of the
already-quirked PNY Pro Elite SSDs (154b:f00b and 154b:f00d). Like its
siblings, it uses a Phison-based USB-SATA bridge that exhibits
firmware bugs when bound to the uas driver.

Without quirks, the device fails to complete READ CAPACITY commands
when accessed over UAS on a SuperSpeed (USB 3) port. The device
enumerates and reports as a SCSI direct-access device, but reports
zero logical blocks and never finishes spin-up:

    usb 2-3: new SuperSpeed USB device number 8 using xhci_hcd
    usb 2-3: New USB device found, idVendor=154b, idProduct=f009
    usb 2-3: Product: PNY ELITE PSSD
    usb 2-3: Manufacturer: PNY
    scsi host0: uas
    scsi 0:0:0:0: Direct-Access     PNY      PNY ELITE PSSD   0
    sd 0:0:0:0: [sda] Spinning up disk...
    [...10+ seconds of polling, no progress...]
    sd 0:0:0:0: [sda] Read Capacity(16) failed: hostbyte=DID_ERROR
    sd 0:0:0:0: [sda] Read Capacity(10) failed: hostbyte=DID_ERROR
    sd 0:0:0:0: [sda] 0 512-byte logical blocks: (0 B/0 B)

Tested each individual quirk to find the minimum that fixes this:
  - US_FL_NO_ATA_1X alone: device hangs on spin-up
  - US_FL_NO_REPORT_OPCODES alone: works on USB 2.0, hangs on USB 3.0
  - US_FL_NO_ATA_1X | US_FL_NO_REPORT_OPCODES: works on both

With both quirks the device enumerates correctly while still using
the uas driver, and delivers full UAS throughput (~281 MB/s
sequential read on a USB 3.0 Gen 1 port).

The existing PNY Pro Elite entries (f00b, f00d) only set NO_ATA_1X,
but this device additionally chokes on REPORT OPCODES under
SuperSpeed.

Signed-off-by: Sam Burkels <sam@1a38.nl>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20260501132346.86572-1-sam@1a38.nl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:12:47 +02:00
Stephen J. Fuhry
9ddb9c0dec USB: quirks: add NO_LPM for Lenovo ThinkPad USB-C Dock Gen2 hub controllers
The Lenovo ThinkPad USB-C Dock Gen2 (17ef:a391, 17ef:a392) hub
controllers exhibit link instability when USB Link Power Management
is enabled, similar to the dock's Ethernet adapter (17ef:a387) which
already carries USB_QUIRK_NO_LPM.

When the dock reconnects after a transient disconnect, the hub
controllers enter LPM states between re-enumeration retries, causing
repeated disconnect/reconnect cycles lasting up to two minutes.
Disabling LPM for these devices restores stable enumeration.

Signed-off-by: Stephen J. Fuhry <fuhrysteve@gmail.com>
Cc: stable <stable@kernel.org>
Link: https://patch.msgid.link/20260513171419.44849-1-fuhrysteve@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 11:12:34 +02:00
Heitor Alves de Siqueira
121d2f682b usb: usbtmc: reject interrupt endpoints with small wMaxPacketSize
The USB488 subclass specification requires interrupt wMaxPacketSize to
be 0x02, unless the device sends vendor-specific notifications.
Endpoints that advertise less than 2 bytes for wMaxPacketSize are
unlikely to work with the current driver, as URBs will not have enough
space for interrupt headers. Considering that any notification URBs will
be ignored by the driver, reject these endpoints early during probe.

Fixes: 041370cce8 ("USB: usbtmc: refactor endpoint retrieval")
Cc: stable <stable@kernel.org>
Suggested-by: Michal Pecio <michal.pecio@gmail.com>
Signed-off-by: Heitor Alves de Siqueira <halves@igalia.com>
Link: https://patch.msgid.link/20260505-usbtmc-iin-size-v3-2-a36113f62db7@igalia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:36:13 +02:00
Heitor Alves de Siqueira
52f2ad3f7e usb: usbtmc: check URB actual_length for interrupt-IN notifications
USBTMC devices can use an optional interrupt endpoint for notification
messages. These typically contain two-byte headers indicating the
payload format, but the driver does not check if these headers are
present before accessing the data buffers. In cases where the URB
actual_length is not enough to fit these headers, the driver will either
cause an out-of-bounds read, or consume stale leftover data from a
previous notification.

Fix by checking if actual_data contains enough bytes for the headers,
otherwise resubmit URB to the interrupt endpoint.

Fixes: dbf3e7f654 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation.")
Reported-by: syzbot+abbfd103085885cf16a2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=abbfd103085885cf16a2
Cc: stable <stable@kernel.org>
Suggested-by: Michal Pecio <michal.pecio@gmail.com>
Signed-off-by: Heitor Alves de Siqueira <halves@igalia.com>
Link: https://patch.msgid.link/20260505-usbtmc-iin-size-v3-1-a36113f62db7@igalia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:36:06 +02:00
Wei-Cheng Chen
5a4c828b8b xhci: tegra: Fix ghost USB device on dual-role port unplug
When a USB device is unplugged from the dual-role port, the device-mode
path in tegra_xhci_id_work() explicitly clears both SS and HS port power
via direct hub_control ClearPortFeature(POWER) calls. This preempts the
xHCI controller's normal disconnect processing -- PORT_CSC is never
generated, the USB core never sees the disconnect, and the device remains
in its internal tree as a ghost visible in lsusb.

Add an otg_set_port_power flag to control whether the dual-role switch
path performs explicit port power management. SoCs that need it
(Tegra124 / Tegra210 / Tegra186) set the flag; later SoCs (Tegra194 and
beyond) rely on the PHY mode change to handle disconnect naturally and
skip all port power calls.

Within the port power path, otg_reset_sspi additionally gates the SSPI
reset sequence on host-mode entry for SoCs that require it.

Flags set per SoC:
  Tegra124, Tegra186  -> otg_set_port_power
  Tegra210            -> otg_set_port_power, otg_reset_sspi
  Tegra194 and later  -> (none)

Fixes: f836e78430 ("usb: xhci-tegra: Add OTG support")
Cc: stable <stable@kernel.org>
Signed-off-by: Wei-Cheng Chen <weichengc@nvidia.com>
Link: https://patch.msgid.link/20260505112630.217704-1-weichengc@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:35:50 +02:00
Kai Aizen
68aa70648b usb: gadget: uvc: hold opts->lock across XU walks in uvc_function_bind
uvc_function_bind() walks &opts->extension_units twice without holding
opts->lock:

  - directly, for the iExtension string-descriptor fixup loop;
  - indirectly, four times via uvc_copy_descriptors() (once per speed),
    where the helper iterates uvc->desc.extension_units (which aliases
    &opts->extension_units) to size and emit XU descriptors.

The configfs side (uvcg_extension_make / uvcg_extension_drop, in
drivers/usb/gadget/function/uvc_configfs.c) takes opts->lock around its
list_add_tail / list_del operations.  A privileged userspace process
that holds the configfs subtree open and writes the gadget UDC name
to bind the function while concurrently rmdir()'ing an extensions
subdir can race uvcg_extension_drop() against the bind-time list walks
and dereference a freed struct uvcg_extension.

Hold opts->lock from the start of the XU string-descriptor fixup
through the last uvc_copy_descriptors() call, releasing on the
descriptor-error path via a new error_unlock label that drops the
lock before falling through to the existing error label.  This
matches the locking discipline of the configfs callbacks and removes
the only remaining unsynchronised reader of the XU list during bind.

Reachability: only privileged processes that can mount configfs and
write to gadget UDC files can trigger the race, so this is a
correctness fix rather than a security boundary.

Fixes: 0525210c98 ("usb: gadget: uvc: Allow definition of XUs in configfs")
Cc: stable <stable@kernel.org>
Signed-off-by: Kai Aizen <kai.aizen.dev@gmail.com>
Link: https://patch.msgid.link/20260430175643.67120-1-kai.aizen.dev@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:35:36 +02:00
Guangshuo Li
c8547c7498 usb: gadget: net2280: Fix double free in probe error path
usb_initialize_gadget() installs gadget_release() as the release
callback for the embedded gadget device.  The struct net2280 instance is
therefore released through gadget_release() when the gadget device's last
reference is dropped.

The probe error path calls net2280_remove(), which tears down the
partially initialized device and drops the gadget reference with
usb_put_gadget().  Calling kfree(dev) afterwards can free the same object
again.

Drop the explicit kfree() and let the gadget device release callback
handle the final free.  This issue was found by a static analysis tool
I am developing.

Fixes: f770fbec41 ("USB: UDC: net2280: Fix memory leaks")
Cc: stable <stable@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://patch.msgid.link/20260427153651.337846-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:35:22 +02:00
Guangshuo Li
4f88d65def usb: gadget: f_hid: fix device reference leak in hidg_alloc()
hidg_alloc() initializes hidg->dev with device_initialize() before
calling dev_set_name(). If dev_set_name() fails, the function currently
jumps to err_unlock and returns without calling put_device().

This leaves the device reference unbalanced and prevents hidg_release()
from being called. Calling put_device() here is also safe, since
hidg_release() only frees resources owned by hidg.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Route the dev_set_name() failure path through err_put_device so the
device reference is dropped properly.

Fixes: 89ff3dfac6 ("usb: gadget: f_hid: fix f_hidg lifetime vs cdev")
Cc: stable <stable@kernel.org>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Johan Hovold johan@kernel.org
Link: https://patch.msgid.link/20260413142119.2977716-1-lgs201920130244@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:34:06 +02:00
Wentao Liang
e194ce048f usb: musb: omap2430: Fix use-after-free in omap2430_probe()
In omap2430_probe(), of_node_put(np) is called prematurely before the
last access to np, leading to a use-after-free if the node's reference
count drops to zero. Move the of_node_put() calls after the last use of
np in both the success and error paths.

Fixes: ffbe2feac5 ("usb: musb: omap2430: Fix probe regression for missing resources")
Cc: stable <stable@kernel.org>
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Link: https://patch.msgid.link/20260409101104.480623-1-vulab@iscas.ac.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-22 10:33:43 +02:00