cleanup_offline_cgwbs_workfn() drains a dying cgwb by calling
cleanup_offline_cgwb() until it returns false, with a cond_resched()
between passes. On a CONFIG_PREEMPTION kernel that cond_resched() does
nothing: _cond_resched() is a plain "return 0", and under PREEMPT_DYNAMIC
the full and lazy modes disable it. Since commit 7dadeaa6e8 ("sched:
Further restrict the preemption modes") those are the only two models on
the architectures with PREEMPT_LAZY support, arm64 and x86 among them, so
the drain loop never reports a Tasks-RCU quiescent state.
A worker draining a cgwb with millions of attached inodes runs for
minutes. On a 6.18 arm64 host in lazy mode the cgwb worker drained one
dying cgroup's writeback domain for over 11 minutes. A BPF program unlink
(bpf_trampoline_unlink_prog -> bpf_trampoline_update ->
unregister_ftrace_direct -> ftrace_shutdown -> synchronize_rcu_tasks())
waited on that grace period while holding the trampoline mutex, 42 tasks
queued behind it in D state, and the hung task detector fired at 614 s and
panicked the host. Any BPF or ftrace detach during a long drain inherits
the drain's length.
Fix this by calling cond_resched_tasks_rcu_qs() so we do not stall out
anybody who calls sycnrhonize_rcu_tasks(). We put this in a do { } while
loop because if we have many small cgroups cleanup_offline_cgwb() will
return false and we will never call cond_resched_tasks_rcu_qs(), creating
the same problem.
Link: https://lore.kernel.org/20260909-cgwb-tasks-rcu-qs-v1-1-967a7754771f@toxicpanda.com
Fixes: c22d70a162 ("writeback, cgroup: release dying cgwbs by switching attached inodes")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/bpf/9d444098-7c03-4163-af12-bd0a79a51443@paulmck-laptop/
Assisted-by: LLM
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
DAMOS can suddenly stop working if a target process that the quota is just
fully charged on is terminated. Fix by catching and processing the corner
case.
When DAMOS quota is fully charged, the target and the region to continue
applying the action in the next round is saved in
damos_quota->charge_{target,addr}_from. In the next round, DAMOS iterates
targets and regions from the beginning. It skips applying the action to
the regions until it visits and skips the saved target/region.
Virtual address space targets become invalid if the process is terminated.
Trying to apply the scheme to invalid target is just a waste of time.
Hence commit 6e4930e333 ("mm/damon/core: fix wasteful CPU calls by
skipping non-existent targets") made the logic to skip invalid targets.
However, it does skip before the charged target/region skipping/updating.
Let's suppose the user runs DAMOS for multiple virtual address spaces with
a quota. The quota exceeded in the middle of a virtual address space.
And the process of the address space is terminated. Then the
charge_target_from points to the invalid target. The pointer update logic
is skipped for the invalid target, so the charge_target_from is never
updated. DAMOS action to every target/region is skipped. From the user's
perspective, it would look like suddenly DAMOS has stopped working.
No critical leak or crash can happen. The user could reinstall the
scheme. But this makes use of DAMOS under certain setups quite
unreliable.
When the invalid target is found, further check the corner case and reset
the pointer.
This issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260910142846.172957-1-sj@kernel.org
Link: https://lore.kernel.org/20260830064708.40CA61F000E9@smtp.kernel.org [1]
Fixes: 6e4930e333 ("mm/damon/core: fix wasteful CPU calls by skipping non-existent targets")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Enze Li <lienze@kylinos.cn>
Cc: <stable@vger.kernel.org> # 7.0.x
Baoquan and I have been contributing MGLRU patches and helping review
MGLRU related patches for some time. We will continue to follow MGLRU
changes, so we'd like to be CC'd on MGLRU related patches.
Link: https://lore.kernel.org/06e20ef4f603a4ffeafcdbf623ce2936281457bf.1788831480.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Acked-by: Baoquan He <baoquan.he@linux.dev>
Acked-by: Kairui Song <kasong@tencent.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
On arm64 server, we find that a task trying to grab the anon_vma lock
triggers hungtask.
INFO: task main:2354726 blocked for more than 120 seconds.
Tainted: G E 5.10.0-0021.aarch64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:main state:D stack: 0 pid:2354726 ppid:2350673 flags:0x00000a01
Call trace:
__switch_to+0x7c/0xbc
__schedule+0x3b4/0x8a0
schedule+0x50/0xe0
rwsem_down_write_slowpath+0x3cc/0x6cc
down_write+0x60/0x260
__anon_vma_prepare+0x6c/0x210
do_anonymous_page+0x258/0x660
handle_pte_fault+0x188/0x214
__handle_mm_fault+0x1b0/0x380
handle_mm_fault+0xf4/0x284
do_page_fault+0x19c/0x494
do_translation_fault+0xcc/0xf8
do_mem_abort+0x48/0xac
el0_da+0x44/0x80
el0_sync_handler+0x88/0xb4
el0_sync+0x160/0x180
After analyzing the vmcore, we found the anon_vma->root->rwsem.count is
-1. There is another anon_vma whose anon_vma->root->rwsem.count is 1, the
anon_vma->root->rwsem.owner shows the lock is held, but the stack of the
task shows the task doesn't hold the anon_vma lock.
After adding more debugging info, we found __anon_vma_prepare() reuses
anon_vma and triggers the UAF of anon_vma->root due to missing memory
barrier, leading to locking and unlocking two different anon_vma->root,
thus leading to an anon_vma will never be unlocked, and another anon_vma
couldn't be locked anymore.
This race requires two adjacent VMAs that are not merged but are
anon_vma-compatible (e.g., they differ in VMA_ACCESS_FLAGS that can be
changed by mprotect()). Two threads fault on each VMA concurrently, both
calling __anon_vma_prepare() with only mmap_lock held for reading.
THREAD A THREAD B
__anon_vma_prepare __anon_vma_prepare
find_mergeable_anon_vma() -> NULL
anon_vma = anon_vma_alloc();
anon_vma->root = anon_vma;
// the two stores may be reordered
vma->anon_vma = anon_vma;
// finds A's anon_vma
anon_vma = find_mergeable_anon_vma(vma);
anon_vma_lock_write(anon_vma);
// may still see the old root
down_write(&anon_vma->root->rwsem);
anon_vma_unlock_write(anon_vma);
// see the new root, never unlock old
up_write(&anon_vma->root->rwsem);
thread A triggers page fault and calls __anon_vma_prepare() to prepare
anon_vma for the faulting vma. __anon_vma_prepare() allocates and
initializes a new anon_vma, and then publishes it to the vma with a plain
store. anon_vma_prepare() only requires the mmap_lock to be held for
reading, so two threads can fault on adjacent VMAs at the same time.
While thread A publishes a new anon_vma, thread B could find the anon_vma
via find_mergeable_anon_vma() and then locks anon_vma->root->rwsem.
The store to anon_vma->root in anon_vma_alloc() and the store to
vma->anon_vma can be reordered. The anon_vma_lock_write() and spin_lock()
only provide acquire semantics, which do not prevent prior stores from
being reordered after them. The release semantics of the corresponding
spin_unlock() and anon_vma_unlock_write() come too late, the store to
vma->anon_vma is already published before they take effect. As a result,
thread B can observe the following order:
vma->anon_vma = anon_vma;
anon_vma->root = anon_vma;
The anon_vma slab is SLAB_TYPESAFE_BY_RCU, so a newly allocated anon_vma
may reuse memory from a previously freed one. The constructor
(anon_vma_ctor) does not reset anon_vma->root, and __put_anon_vma()
doesn't clear it either, so the old root value persists until
anon_vma_alloc() overwrites it. If that store isn't visible, thread B
reads a root that points to the old anon_vma and locks it.
As a result, thread B can call anon_vma_lock_write() with the old root,
and call anon_vma_unlock_write() with the new root, leading to an anon_vma
will never be unlocked, and another anon_vma couldn't be locked anymore
(its count is dropped from 0 to -1 due to wrong unlock).
To fix it, change the plain store `vma->anon_vma = anon_vma` to store
release, so that the fields of anon_vma are visible before anon_vma is
published to vma->anon_vma.
At read side, the load of anon_vma and anon_vma->root have address
dependency. According to Documentation/memory-barriers.txt and some
investigations, only Alpha needs address-dependency barriers and it has
been handled by READ_ONCE() in reusable_anon_vma().
We reproduced this issue in v5.10 with KSM enabled. The kernel doesn't
merge commit cf7e7a3503 ("mm: prevent KSM from breaking VMA merging for
new VMAs"), so there are many adjacent VMAs that aren't merged but are
compatible for anon_vma.
Without this fix, our production environment could reproduce this issue
about 2-5 times each month. After adding a smp_mb() before
anon_vma_lock_write(anon_vma) in __anon_vma_prepare(), which is different
to this patch, this issue hasn't been reproduced for one month.
Link: https://lore.kernel.org/20260908122924.554373-1-tujinjiang@huawei.com
Fixes: 5c341ee1df ("mm: track the root (oldest) anon_vma")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jinjiang Tu <tujinjiang@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: <stable@vger.kernel.org>
move_hugetlb_page_tables() optimizes mremap() by advancing to the last
entry in the page table when the source page table does not exist, either
initially or after unsharing a PMD table. The common loop increment then
steps to the first entry in the next page table.
However, the code advances both the source and destination addresses to
the last entries in their respective page tables, which is wrong. The
destination address must be advanced only by the same amount as the source
address.
If the source and destination offsets within their page tables differ, the
destination address can be advanced too far, causing follow-up issues.
Fix this by advancing the destination address by the source advance
distance.
With a reproducer, we were able to trigger a kernel panic on x86-64. With
this fix in place, we can no longer reproduce the issue.
Link: https://lore.kernel.org/20260914132352.472-1-jaewook376@gmail.com
Fixes: e95a985178 ("hugetlb: skip to end of PT page mapping when pte not present")
Fixes: 4ddb4d91b8 ("hugetlb: do not update address in huge_pmd_unshare")
Signed-off-by: Jaewook You <jaewook376@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Assisted-by: LLM
Once quota set, the charge_{target,addr}_from unconditionally skips and
resets at the last region of the tracked target, so the last region can be
skipped even when it has not been processed.
Example:
1. Target has 2 regions: R1 (0-100 bytes) and R2 (100-200 bytes).
2. Quota is configured to process only 100 bytes per window.
3. Window 1: Processes R1 (0-100). Quota is full. charge_{target,
addr}_from is saved at (Target, 100).
4. Window 2: The loop reaches R2. Because R2 is
damon_last_region(t), the old code unconditionally returns true,
skipping R2 entirely and resetting the charge_{target,addr}_from.
Result: R2 is permanently skipped even though it has never been
processed.
However, it is important to note that this is a very minor issue. This is
because it is triggered only when the previous window saved/kept
charge_{target,addr}_from, and in the next window, all regions except the
last region were skipped by damos_skip_charged_region().
Fix this by only resetting the charge_{target,addr}_from when last region
is reached, only skipping when it is applied or cannot split.
Link: https://lore.kernel.org/20260908134739.96919-1-sj@kernel.org
Fixes: 50585192bc ("mm/damon/schemes: skip already charged targets and regions")
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org> # v5.16.x
damon_hugetlb_mkold() reads the page table entry into a local variable,
unsets the accessed bit in the variable, and updates the page table entry
with the updated variable value. If hardware updates the same page table
entry in parallel, the hw updates could be lost. For example,
hardware-updated dirty bits might be lost.
Avoid the parallel updates by clearing the page table entry when reading
it together, using huge_ptep_get_and_clear(). If a parallel write to the
memory is made after the clearing, the hw will see the page table entry is
cleared, trigger page fault and wait until it is handled. The page fault
handling will wait for damon_hugetlb_mkold() due to the page table lock.
Because hugetlbfs is an in-memory file system and hugetlb pages cannot be
reclaimed, no critical issue is expected to my best knowledge. But
definitely this is a nasty bug that should be fixed sooner rather than
later.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260907170358.100168-1-sj@kernel.org
Link: https://lore.kernel.org/20260830160545.98969-1-sj@kernel.org [1]
Fixes: 49f4203aae ("mm/damon: add access checking for hugetlb pages")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: <stable@vger.kernel.org> # 5.17.x
When the temporal quota goal tuner determines that the goal has been
achieved (score >= 10000), it sets esz_bp to zero so that the esz becomes
zero. However, damos_set_effective_quota() clamps the esz to
min_region_sz when quota->ms is set.
This is a minor issue, the main problem is that it doesn't match the
description in the documentation, which state that if the goal has already
been [over-]achieved, the quota will be set to zero.
Fix this by set quota (esz) as minimum as possible.
Link: https://lore.kernel.org/20260908135413.97570-1-sj@kernel.org
Fixes: 8bbde987c2 ("mm/damon/core: disallow time-quota setting zero esz")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # v7.1.x
__damon_va_prepare_access_check() picks a random byte address within the
region and stores it in r->sampling_addr. damon_va_mkold() passes it into
a page table walk, which hands it to damon_ptep_mkold() as the address of
the page to sample:
damon_va_mkold(mm, r->sampling_addr)
damon_va_walk_page_range(mm, addr, addr + 1)
damon_mkold_pmd_entry()
damon_ptep_mkold(pte, vma, addr)
ptep_test_and_clear_young(vma, addr, pte)
mmu_notifier_clear_young(mm, addr, addr + PAGE_SIZE)
For arm64, before commit 6f0e114217 ("arm64: mm: support batch clearing
of the young flag for large folios"), the contpte helper walked exactly
CONT_PTES entries from the aligned-down page table pointer and used @addr
only to pass down to each entry, so an unaligned value was harmless:
ptep = contpte_align_down(ptep);
addr = ALIGN_DOWN(addr, CONT_PTE_SIZE);
for (i = 0; i < CONT_PTES; i++, ptep++, addr += PAGE_SIZE)
Now the range to walk is derived from @addr instead: end = addr + nr *
PAGE_SIZE, rounded up to CONT_PTE_SIZE. For a sample in the last page of
a contpte block, the sub-page offset puts end just past the block
boundary, so the round-up lands a whole block further and the walk clears
PTE_AF in CONT_PTES entries beyond the sampled block. For the last block
in a page table page, those entries are past the end of that page, so the
walk writes into the page that follows.
Triggered by the full 7.1/7.2 kernel selftest suite on arm64 (EC2
c/m6g.4xlarge). The kernel sometimes crashes at or shortly after the
DAMON test.
What the overrun does depends on the page that happens to follow the page
table, so there is no single signature. If that page is read-only, the
write faults in the sampling path itself:
Unable to handle kernel write to read-only memory at virtual address ffff0003c5d2d000
FSC = 0x0f: level 3 permission fault
CM = 0, WnR = 1, TnD = 0, TagAccess = 0
CPU: 10 UID: 0 PID: 3487 Comm: kdamond.2
pc : contpte_test_and_clear_young_ptes+0x70/0xc0
lr : damon_ptep_mkold+0x1e8/0x1f8
Call trace:
contpte_test_and_clear_young_ptes+0x70/0xc0 (P)
damon_mkold_pmd_entry+0x150/0x170
walk_pmd_range+0x110/0x2b0
walk_pud_range+0x10c/0x208
walk_pgd_range+0x134/0x258
__walk_page_range+0x98/0x1b0
walk_page_range_vma_unsafe+0x90/0x148
walk_page_range_vma+0x28/0x40
damon_va_walk_page_range+0x114/0x2b8
damon_va_prepare_access_checks+0xec/0x1a8
kdamond_fn+0x534/0x770
kthread+0x128/0x138
ret_from_fork+0x10/0x20
Otherwise the page is writable, the PTE_AF clearing succeeds silently and
the damage only surfaces later, in whatever happened to own the page, so
the backtrace is unrelated to DAMON and differs between runs.
Pass a page-aligned address to the ptep_test_and_clear_young() call in
damon_ptep_mkold(), which is the only place DAMON can reach
contpte_test_and_clear_young_ptes() from. Nothing else sees the aligned
address, and r->sampling_addr itself is left as is, so the sampling and
region bookkeeping semantics are unchanged.
Link: https://lore.kernel.org/20260904002829.116381-1-sj@kernel.org
Fixes: 6f0e114217 ("arm64: mm: support batch clearing of the young flag for large folios")
Signed-off-by: Nathan Gao <zcgao@amazon.com>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: <stable@vger.kernel.org>
ocfs2_calc_xattr_init() used to read the default ACL off the parent inode
itself, so it could return an error from ocfs2_xattr_get_nolock(). Commit
bd7c05fb4a ("ocfs2: fix circular locking dependency in
ocfs2_init_acl()") moved that lookup before the transaction starts and
deleted the error path, but left the now vestigial 'int ret = 0'
declaration and both 'return ret' statements behind, along with an
unreachable error branch in ocfs2_mknod().
Drop the leftover variable and convert the return type to void, so the
callee states that it always succeeds and the caller no longer carries a
check that can never trigger.
No functional change.
Link: https://lore.kernel.org/20260904023751.3703334-1-joseph.qi@linux.alibaba.com
Fixes: bd7c05fb4a ("ocfs2: fix circular locking dependency in ocfs2_init_acl()")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202609040247.8B3lmoqX-lkp@intel.com/
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
The test_no_invasive_cgroup_shrink selftest checks that when a cgroup has
zswapped out more memory than memory.zswap.max, it does not trigger
writeback for other cgroups. To do this, it compares the writeback count
in a control cgroup and makes sure that it is 0, and then checks the
writeback count in an aggressor cgroup who does expect to see writeback.
However, when the zswap shrinker is enabled, the victim cgroup can see
legitimate writebacks not triggered by the aggressor. In some Meta CI
tests, we have seen this failure mode happen.
Instead of checking that the victim cgroup has 0 writeback, compare the
writeback values before and after the aggressor runs and check that the
victim cgroup did not perform any additional writeback. Note that this
can still lead to probabilistic failures if writebacks take longer than
5 seconds, but this should fix the systematic failure case and make
"not ok test_no_invasive_cgroup_shrink" less likely.
Link: https://lore.kernel.org/20260902194521.3652178-1-joshua.hahnjy@gmail.com
Fixes: b5ba474f3f ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Krush Chavan <krushchavan@outlook.com>
Suggested-by: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org>
da9063_wdt_suspend() and da9063_wdt_resume() only check watchdog_active(),
when the watchdog is left running by the driver sets
WDOG_HW_RUNNING in da9063_wdt_probe() but userspace never opens the
device, so WDOG_ACTIVE remains cleared, the wdt_disable() will not be
executed in da9063_wdt_suspend. In this case, the suspend callback is
a no-op and the watchdog keeps counting during system suspend,
leading to an unexpected system reset.
Check WDOG_HW_RUNNING and wdd，can fix this issue.
Fixes: a7ceca4398 ("watchdog: da9063: optionally disable watchdog during suspend")
Cc: stable@vger.kernel.org
Signed-off-by: Li Jun <lijun01@kylinos.cn>
Link: https://patch.msgid.link/20260917013710.2754679-1-lijun01@kylinos.cn
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
parisc is one of the few architectures that does not call
parse_early_param() from setup_arch(). That was mostly harmless until
commit d49004c5f0 ("arch, mm: consolidate initialization of nodes,
zones and memory map") moved the consumer of several hugetlb command
line parameters into mm_core_init_early(), which runs before the
generic parse_early_param() call in start_kernel().
As a result hugepages=, hugepagesz=, default_hugepagesz=, hugetlb_cma=
and hugetlb_free_vmemmap= are recorded after they have already been
consumed and are silently dropped on parisc.
Call parse_early_param() from setup_arch(), after the command line has
been set up and the memory inventory has been taken. jump_label_init()
must be called first because early parameter handlers may enable or
disable static keys. Both functions are safe to call more than once:
the generic calls in start_kernel() remain in place and turn into no-ops.
Suggested-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Fixes: d49004c5f0 ("arch, mm: consolidate initialization of nodes, zones and memory map")
Cc: <stable@vger.kernel.org>
Signed-off-by: Zhenghui Hao <zhenghui.hao@qq.com>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
The last use of arch/parisc/include/asm/compat_ucontext.h was removed
in commit d313d4e72d ("parisc: remove unused compat_rt_sigframe.h
header") but it was left behind. Remove it.
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
There is a bug in the binary search where hi can underflow. If
addr is less than the first entry, then "hi = mid - 1" will underflow
to ULONG_MAX. Then we have an out-of-bounds read.
Replace the open-coded binary search with bsearch().
Issue found by an LLM.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Helge Deller <deller@gmx.de>
__is_affected_midr_range() is handed the MIDR and REVIDR of one target
implementation CPU, but tests the erratum's range with is_midr_in_range(),
which re-scans all of target_impl_cpus[] and ignores the @midr argument.
The range test is thus constant across the per-CPU loop in
is_affected_midr_range() and only answers "is any target CPU in range".
Since just the fixed_revs REVIDR check uses the iteration's own registers,
an out-of-range target CPU can decide whether a MIDR_FIXED() exemption
applies. A VM then enables a workaround whose only in-range CPU is fixed
silicon, e.g. erratum 2658417 on a Cortex-A510 r1p1 with REVIDR_EL1[25]
set.
Factor the range test into __is_midr_in_range(), which takes an explicit
MIDR, and use it in __is_affected_midr_range().
Fixes: 86edf6bdcf ("smccc/kvm_guest: Enable errata based on implementation CPUs")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
Add an override for WFxT support within ID_AA64ISAR2_EL1 to allow
it to be disabled using the new arm64.nowfxt command line parameter.
This accompanies the idle=nop param introduced in a previous patch
series [1] in dealing with misbehaving WFI and WFIT instructions on
Apple Silicon SoCs, and eases debugging of other quirky WFxT
implementations.
Link[1]: https://lore.kernel.org/all/20260804-arm64-idle-param-v3-1-d10f8159062b@cyberchaos.dev/
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Yureka Lilian <yureka@cyberchaos.dev>
Signed-off-by: Will Deacon <will@kernel.org>
Mapping a stack-top page via /dev/mem with PROT_NONE and then
reading that process's /proc/<pid>/cmdline triggers a spurious WARN
in ioremap_prot() through generic_access_phys():
WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys
Call trace:
generic_access_phys+0x1c8/0x228 (P)
__access_remote_vm+0x2b4/0x398
access_remote_vm+0x14/0x30
get_mm_cmdline+0xf8/0x2a0
proc_pid_cmdline_read+0x68/0x120
generic_access_phys() passes the protection derived from the user PTE
to ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a
present-invalid PTE, so pte_present() still returns true and the
protection reaches ioremap_prot().
A PROT_NONE mapping does not have PTE_USER, causing the existing
WARN_ON_ONCE() in ioremap_prot() to fire even though this is a valid
user mapping. Execute-only mappings have the same issue and must not
be readable through this path either.
ioremap_prot() should therefore reject protection values without
PTE_USER without warning. This makes the access fail cleanly for
PROT_NONE and execute-only mappings while retaining the existing
user-protection contract.
Fixes: 8f09803713 ("arm64: io: Extract user memory type in ioremap_prot()")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
The current special-case for EVICT_STATE_SEL filtering effectively
assigns the "filter" and "filter2" controls in the opposite order from
how the CMN S3 r2 TRM states "Filtering is programmed in pmu_hbt_lbt_sel
and pmu_evict_state_sel". On reflection, not only does this seem
unnecessarily non-obvious to users, but it's also likely to be a problem
for scaling to a full multi-filter abstraction in future. There is a
logical order to filters based on their bitfield positions in the
pmu_event_sel register, which the TRM descriptions allude to, and the
cmn_filter_select enum already (almost) follows, so let's fix the UABI
to follow suit while it's still unreleased.
Fixes: 09178f536b ("perf/arm-cmn: Plumb in new filter types")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Here are two fixes for a long-standing baud rate overflow issue in the
two Quatech drivers and a new cp210x device id.
Everything has been in linux-next with no reported issues.
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Merge tag 'usb-serial-7.3-rc4' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus
Johan writes:
USB serial fixes for 7.3-rc4
Here are two fixes for a long-standing baud rate overflow issue in the
two Quatech drivers and a new cp210x device id.
Everything has been in linux-next with no reported issues.
* tag 'usb-serial-7.3-rc4' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial:
USB: serial: quatech2: fix baud rate overflow
USB: serial: ssu100: fix baud rate overflow
USB: serial: cp210x: add Corsair AX1500i Power Supply
Add a test of the signal ABI for INT instructions in both 32-bit and
64-bit processes. Check the signal number, trap number, error code,
si_code, si_addr, instruction pointer and RF/TF state against legacy
IDT behavior. Include a 15-byte prefixed INT to check that IP uses the
hardware instruction length. Exercise both INT3 encodings, INT4, UD2
and HLT to cover the unchanged trap and fault paths.
Run each instruction with TF clear and set. Resume at a known NOP after
handling the signal and check that single-stepping traps after the NOP.
Also drive INT 0x2d under ptrace, which resumes through the fault frame
rather than sigreturn and so exposes a stale FRED software event flag.
Start from an INT3 stop, whose FRED frame has no software event flag,
instead of the syscall frame of raise(SIGSTOP). Single-step into the INT
and check that the fault reports its address. Then suppress SIGSEGV and
resume at the NOP, once with PTRACE_SINGLESTEP and once with PTRACE_CONT
and TF set. Section 6.2.3 of the Intel FRED specification [1] specifies
the immediate single-step trap caused by returning with both that flag
and TF set. Check that each trap occurs after the NOP, rather than at
its address.
Report whether the CPU supports FRED, since a pass looks the same on
either entry path. INT 0x80 with IA32 emulation disabled and a 64-bit
tracer of a 32-bit tracee are not covered.
Both variants pass all 29 checks on a non-FRED AMD host and on Panther
Lake with FRED enabled and the fix applied. With the same binaries on
unpatched Panther Lake, 16 signal-context checks fail and the first
ptrace check reports the IP after the INT. The two dependent ptrace
resume checks are not reached.
[1] Intel Flexible Return and Event Delivery (FRED) Specification,
revision 9.0 (346446-009US), section 6.2.3.
Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://cdrdv2.intel.com/v1/dl/getContent/678938 # [1]
Link: https://patch.msgid.link/20260917230907.2080792-3-matthew.schwartz@linux.dev
FRED event delivery does not use the IDT, so the gate DPL check that
rejects a user INT n falls to software (Intel FRED specification [1],
section 8.3). fred_intx() rejects the same vectors as IDT delivery, but
reports a zero error code and the IP after the INT. This breaks the
signal ABI. Wine uses the error code to recognize INT 0x2d, so the
changed context turns a handled breakpoint into an access violation in
Elden Ring.
Rewind IP using the instruction length in the augmented SS and
synthesize the IDT selector error code, (vector << 3) | 2. Set RF in the
saved flags, as the CPU does for a #GP fault. Section 5.2.1 defines the
saved vector, instruction length and RF state. The supplied length
handles prefixes without reading user memory. Limit the changes to
already-rejected software interrupts, preserving the accepted INT3, INT4
and enabled INT80 paths and hardware exceptions. With IA32 emulation
disabled, INT 0x80 now reports the same #GP as the DPL 0 gate IDT
installs there. The rewound IP also stops fixup_iopl_exception() from
inspecting the byte after the INT.
Also clear the software event flag. Section 6.2.3 specifies that ERETU
with this flag and TF set traps before executing any user instruction. A
tracer that suppresses SIGSEGV and resumes with TF set expects the next
instruction to run first, as after IRET. The sigreturn path clears the
same flag for this reason in prevent_single_step_upon_eretu().
[1] Intel Flexible Return and Event Delivery (FRED) Specification,
revision 9.0 (346446-009US), sections 5.2.1, 6.2.3 and 8.3.
Fixes: 14619d912b ("x86/fred: FRED entry/exit and dispatch code")
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/work_items/15745
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/work_items/16132
Reported-by: Paul Gofman <pgofman@codeweavers.com>
Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Link: https://cdrdv2.intel.com/v1/dl/getContent/678938 # [1]
Link: https://patch.msgid.link/20260917230907.2080792-2-matthew.schwartz@linux.dev
Proxy execution can move a blocked donor's scheduling context to the
lock owner's CPU even when the donor is migration-disabled. The donor
does not execute there, and its original execution CPU remains recorded
in wake_cpu.
set_task_cpu() warns unconditionally for migration-disabled tasks, so a
subsequent proxy migration or the wakeup path returning the donor home
triggers a false positive: moving a blocked scheduling context does not
violate the migration-disabled execution context.
For example, creating a mutex owner on CPU1 and a migration-disabled
waiter on CPU0 can trigger the following warning:
proxy_migrate_repro: donor blocking on CPU0 with migration disabled
proxy_migrate_repro: donor moved from CPU0 to CPU1
WARNING: kernel/sched/core.c:3389 at set_task_cpu+0x1d3/0x280
...
Call Trace:
try_to_wake_up+0x43f/0x780
__mutex_unlock_slowpath+0x330/0x540
owner_fn+0x9f/0xc0 [proxy_migrate_repro]
...
proxy_migrate_repro: donor woke on CPU0, task_cpu=0
proxy_migrate_repro: completed
Exclude blocked proxy donors from the warning. The proxy wakeup path
restores an executable placement before clearing the blocked state.
Fixes: b049b81bdf ("sched: Handle blocked-waiter migration (and return migration)")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: John Stultz <jstultz@google.com>
Link: https://patch.msgid.link/20260915184101.2621252-1-arighi@nvidia.com
A typical module unload occurring event when there is an active perf
connection leads to freeing of the pmu pointer. The call log is something
like:
..
__pmu_detach_event
pmu_detach_event
pmu_detach_events
perf_pmu_unregister
..
__pmu_detach_event() sets event->pmu to null. When the perf connection
finally is closed, the following stack trace is observed:
Oops: general protection fault, kernel NULL pointer dereference
...
RIP: 0010:_free_event+0x3e/0x370
...
Call Trace:
...
perf_event_release_kernel+0x260/0x2d0
perf_release+0x12/0x20
A call to mediated_pmu_unaccount_event() inside _free_event() is the root
cause of this crash. Adding a check inside is_include_guest_event() ensures
we don't accidentally access a null pmu ptr. In addition to this, we will
now call mediated_pmu_unaccount_event() before clearing the pmu ptr so that
nr_include_guest_events counts are maintained correctly.
Fixes: eff95e1702 ("perf: Add APIs to create/release mediated guest vPMUs")
Assisted-by: Claude:Claude-Sonnet-5
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://patch.msgid.link/20260904181625.1394082-1-vinay.belgaumkar@intel.com
nft_setelem_catchall_insert() looks up duplicates with
nft_set_elem_active() only, while nft_set_catchall_lookup() and the
dump path additionally skip expired elements.
Once a catchall element with a timeout expires, this predicate drift
makes it invisible to userspace dumps, yet it still blocks
re-insertion: with NLM_F_EXCL the request fails with -EEXIST, and
without it the request reports success but silently inserts nothing.
The stale entry only goes away when the (user-tunable) gc interval
elapses, so the catchall rule may silently stop matching for an
arbitrarily long time after its first expiration.
The delete path shows the same drift: nft_setelem_catchall_deactivate()
picks the first active-next entry in the catchall list, so with an
expired entry still pending GC it retires the stale entry instead of
the fresh one, and it deactivates an element that userspace no longer
sees instead of failing with -ENOENT.
Align both walks with the lookup and dump predicates: only an element
that is active and not expired counts as a duplicate or delete
candidate, using the per-netns timestamp taken at transaction start,
in line with the set backend .insert/.deactivate and catchall GC sync
paths.
Reported-by: TencentOS Corvus AI <corvus@tencent.com>
Cc: stable@vger.kernel.org
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Assisted-by: CodeBuddy:Kimi-K3
Signed-off-by: Aohan Mei <henrymei@tencent.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
bpf_binprm_set_interp() tests path[0] != '/' on the buffer its load
program passes and then reads the same buffer again to copy it with
kmemdup_nul(). The buffer can be a BPF map value that another CPU
rewrites between the two reads. If byte 0 is overwritten in that
window, the kfunc stages a relative or empty interpreter path. The
staged path is not checked again, so open_exec() resolves a relative
path against the working directory of the task doing the exec.
bpf_binprm_set_interp_arg() has the same pattern for its "!len" test
and can stage an empty argument, which the interpreter then receives
as an empty argv entry.
The verifier checks the path and path__sz pair with BPF_READ |
BPF_WRITE, so a writable array map value is an accepted argument.
bpf(BPF_MAP_UPDATE_ELEM) on an array map copies the new value over the
old one in place and takes no lock. Both kfuncs are KF_SLEEPABLE and
allocate with GFP_KERNEL between the test and the copy, so the task
can sleep inside the window:
load program bpf(BPF_MAP_UPDATE_ELEM)
bpf_binprm_set_interp()
strnlen(path, path__sz)
path[0] != '/' is false
kmemdup_nul(path, len, GFP_KERNEL)
allocation may sleep
array_map_update_elem()
copy_map_value()
rewrites byte 0
copy reads path again
bm_bpf_stage_selection()
The test in the load program's column proves what byte 0 held only at
the moment the test ran. The map update takes no lock, so it can store
to byte 0 right after. kmemdup_nul() then copies the rewritten bytes,
and bm_bpf_stage_selection() publishes them as bprm->bpf_interp.
The staged path is not checked again on its way to open_exec():
load_misc_binary()
entry_select_interpreter() returns bprm->bpf_interp unchanged
build_interp_argv()
copy_string_kernel() copies it as argv[0]
bprm_change_interp()
kstrdup()
entry_open_interpreter()
open_exec() unless a bound file is staged or
the entry is an 'F' entry
None of these functions tests the first byte, and load_misc_binary()
hands the pointer to nothing else.
In bpf_binprm_set_interp_arg(), strnlen() finds a non-zero len, a NUL
is then stored to byte 0, and build_interp_argv() later copies the
empty bprm->bpf_interp_arg with copy_string_kernel().
The handler's own load program has to pass a writable map value, and
something has to store into it while the kfunc runs. The allocation can
sleep inside the window, and with a BPF_F_MMAPABLE array the store is a
plain user space write into the mapped value, so a loop can hit it
without a single bpf() call.
Check the private copy in both kfuncs, so that the string that gets
staged is the string that was checked. bpf_binprm_select_interp()
already looks its name up in a private copy for the same reason. The
remaining tests work on path__sz, arg__sz or the local len, and the
copy length is len, so the copy stays inside the extent the verifier
checked.
Results of bpf_binprm_set_interp() with the check on the copy:
- A NUL stored to byte 0 fails interp[0] != '/' and gets -EINVAL.
- For len == 0, kmemdup_nul() returns an empty string, so an empty path
still gets -EINVAL.
- A NUL stored further into the string only shortens it to another
absolute path, or another non-empty argument, that the program could
have passed anyway.
- A path that both lacks the leading '/' and is PATH_MAX or longer now
gets -ENAMETOOLONG instead of -EINVAL.
- A path that is empty or lacks the leading '/' is now rejected after
the copy rather than before it, so such a call makes an allocation
and returns -ENOMEM instead of -EINVAL if that allocation fails.
bpf_binprm_set_interp_arg() still rejects an empty argument before
allocating, so its results are unchanged apart from the raced case
fixed here.
Both new checks run before the previously staged string is freed or
replaced. A failing call frees only its own allocation and leaves the
earlier selection in place, as the -ENOMEM path already does.
Fixes: b4bfe2f6b0 ("binfmt_misc: add binfmt_misc_ops bpf struct_ops")
Signed-off-by: Chris Mason <mason@kernel.org>
Link: https://patch.msgid.link/20260918-work-binfmt_misc-fixes-v1-2-647b24bc1c46@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
bpf_binprm_select_interp() checks the name its load program passes with
strnlen(name, name__sz) and then hands the same buffer to
binfmt_misc_find_interp(), which compares it with an unbounded strcmp().
The buffer can be a BPF map value that another CPU rewrites between the
two reads. If the terminating NUL is overwritten in that window, strcmp()
reads past the name__sz bytes the verifier checked. That is an
out-of-bounds read of up to 31 bytes of whatever follows the checked
name__sz bytes.
The verifier checks the name and name__sz pair with BPF_READ | BPF_WRITE,
so a writable array map value is an accepted argument.
bpf(BPF_MAP_UPDATE_ELEM) on an array map copies the new value over the
old one in place and takes no lock. The NUL that strnlen() finds can be
overwritten before strcmp() reads the buffer again:
CPU0 CPU1
bpf_binprm_select_interp()
strnlen(name, name__sz)
finds the NUL inside name__sz
bpf(BPF_MAP_UPDATE_ELEM)
array_map_update_elem()
copy_map_value()
overwrites the NUL
binfmt_misc_find_interp()
strcmp(interp->name, name)
reads past name__sz
strnlen() proves that a NUL lies inside name__sz only at the moment it
runs. The map update on CPU1 takes no lock, so it can store over the NUL
right after. The lookup on CPU0 then walks the live buffer again, once
per bound interpreter:
fs/binfmt_misc.c:binfmt_misc_find_interp
list_for_each_entry(interp, interps, list)
if (!strcmp(interp->name, name))
return interp;
strcmp() stops at the first mismatch or at the end of interp->name.
bm_entry_add_interp() caps a bound name at BINFMT_MISC_INTERP_NAME_MAX
(32) bytes, so strcmp() reads at most 33 bytes of name. The smallest
name__sz the kfunc accepts is 2, which leaves up to 31 bytes read beyond
the checked extent. The handler's own load program has to pass a
writable map value, and something has to store into it while the kfunc
runs. The window between strnlen() and strcmp() is short, but with a
BPF_F_MMAPABLE array the store is a plain user space write into the
mapped value, so a loop can hit it without a single bpf() call.
Copy the name into a stack buffer of BINFMT_MISC_INTERP_NAME_MAX + 1
bytes, terminate it, and look up the copy. The memcpy() length is below
name__sz, so the copy stays inside the extent the verifier checked, and
the BPF buffer is not read again afterwards.
Return -ENOENT first for a name longer than BINFMT_MISC_INTERP_NAME_MAX.
bm_entry_add_interp() rejects a longer name, and the only other binding
site attaches the empty name. No entry can bind such a name, so that
lookup already ended in -ENOENT and no result changes.
Check the first byte of the copy and return -EINVAL if it is NUL, as the
existing "!len" test does for an empty name. Only an 'F' entry binds the
empty name and a 'B' entry cannot carry 'F', so without that check a
racing store of NUL to byte 0 would look up a name no entry binds and
end in -ENOENT rather than -EINVAL. A NUL stored further into the name
only shortens it to another name the program could have passed anyway.
binfmt_misc_find_interp() itself is left alone: entry_attach_interpreter()
calls it with a kernel string, and this kfunc now calls it with a private
copy.
Fixes: 6ec7c96bee ("binfmt_misc: let a 'B' entry bind its interpreters")
Signed-off-by: Chris Mason <mason@kernel.org>
Link: https://patch.msgid.link/20260918-work-binfmt_misc-fixes-v1-1-647b24bc1c46@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
expect_iter_name() is invoked by nf_ct_expect_iterate_net() under
spin_lock_bh(&nf_conntrack_expect_lock). It does not hold
rcu_read_lock().
When accessing exp->helper with rcu_dereference() in syzbot's report,
lockdep warns:
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
net/netfilter/nf_conntrack_netlink.c:3393 suspicious rcu_dereference_check() usage!
locks held by syz-executor381/5628: 2, last CPU#1:
#0: ffffffff9aee42a0 (nfnl_subsys_ctnetlink_exp){+.+.}-{4:4},
at: nfnetlink_rcv_msg+0xa69/0x12b0
#1: ffffffff8ea74d58 (nf_conntrack_expect_lock){+...}-{3:3},
at: nf_ct_expect_iterate_net+0x38/0x180
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150
lockdep_rcu_suspicious+0x140/0x1d0
expect_iter_name+0xfb/0x100
nf_ct_expect_iterate_net+0xf2/0x180
ctnetlink_del_expect+0x45d/0x640
nfnetlink_rcv_msg+0xcc2/0x12b0
netlink_rcv_skb+0x226/0x4a0
nfnetlink_rcv+0x2b9/0x28c0
netlink_unicast+0x7bd/0x940
netlink_sendmsg+0x813/0xb40
____sys_sendmsg+0x54e/0x850
___sys_sendmsg+0x2a5/0x360
__sys_sendmsg+0x2a5/0x360
do_syscall_64+0x166/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Use rcu_dereference_protected() with lockdep_is_held() on
nf_conntrack_expect_lock instead, similar to expect_iter_me() in
nf_conntrack_helper.c.
Fixes: f017941060 ("netfilter: nf_conntrack_expect: use expect->helper")
Reported-by: syzbot+4bd730aede2791e40bdf@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6aa4a377.f81106d8.2ab401.0024.GAE@google.com/T/#u
Signed-off-by: Naman Gulati <namangulati@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
While the outer IP header is already pulled into the skb head, we must
be careful and revalidate the embedded headers after reading them from
the skb frags to prevent possible out-of-bounds access.
One such place reported by Sashiko is ip_vs_in_icmp() where local
process can change the ihl field and after pskb_may_pull() we can see
larger value. Even if icmp_send() has checks to prevent out-of-bounds
access, play safe and add check to drop the packet if the ihl field is
changed. As the outer headers are pulled, make sure the transport
header is updated too, it was used before commit 7fcc2fe39f ("net:
icmp: avoid invalid transport header access in icmp_send tracepoint")
Fixes: f2edb9f770 ("ipvs: implement passive PMTUD for IPIP packets")
Link: https://sashiko.dev/#/patchset/20260806105211.34622-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_synproxy_do_eval() verifies the TCP checksum before it switches on
skb->protocol. It uses nf_ip_checksum(), which constructs an IPv4
pseudo header and relies on the IPv4 header checksum when folding the
whole skb. Neither operation is valid for an IPv6 packet.
A correctly checksummed IPv6 segment can therefore fail verification
when it reaches the hook as CHECKSUM_NONE or, at NF_INET_LOCAL_IN,
CHECKSUM_COMPLETE. nft_synproxy_do_eval() returns NF_DROP before
nft_synproxy_eval_v6() can send a SYN-ACK.
nft_synproxy_validate() deliberately admits NFPROTO_IPV6 and
NFPROTO_INET, and the xtables counterpart ip6t_SYNPROXY.c already calls
nf_ip6_checksum().
Use nf_checksum() with nft_pf() so the checksum helper dispatches to the
packet family's implementation.
Fixes: ad49d86e07 ("netfilter: nf_tables: Add synproxy support")
Assisted-by: LLM
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
rt_mt6_check() permits rules to be configured with rtinfo->addrnr == 0
even when address matching (IP6T_RT_FST_MASK) is requested.
In the IP6T_RT_FST_NSTRICT path, rt_mt6() evaluates packet routing
addresses against rtinfo->addrs[i] and terminates backwards at the bottom
of the loop:
if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
i++;
}
if (i == rtinfo->addrnr)
break;
When addrnr is 0, if the first packet address matches rtinfo->addrs[0],
i is incremented to 1. Because i is now strictly greater than addrnr (0),
the loop termination condition (i == rtinfo->addrnr) is bypassed and will
never be satisfied.
If a crafted IPv6 packet contains matching routing addresses, i will
advance past IP6T_RT_HOPS (16). The subsequent call to ipv6_addr_equal()
reads beyond struct ip6t_rt, triggering UBSAN/KASAN out-of-bounds warnings
or kernel panics.
Fix this by:
1. Rejecting rules in rt_mt6_check() where IP6T_RT_FST_MASK is set but
rtinfo->addrnr is zero.
2. In rt_mt6(), moving the termination condition (i < rtinfo->addrnr)
into the for-loop header condition and removing the backwards break
at the end of the loop body.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Suggested-by: Florian Westphal <fw@strlen.de>
Assisted-by: LLM
Signed-off-by: Luxiao Xu <rakukuip@gmail.com>
Signed-off-by: Ren Wei <weir@nebusec.ai>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip6_route_lookup() can return an error-free route whose rt6i_idev is
NULL. Lowering an external nexthop device's MTU below IPV6_MIN_MTU tears
down its inet6_dev while fib6_ifdown() leaves routes using nexthop objects
in the FIB. An unprivileged user can construct this state with rtnetlink
in a private user and network namespace, then trigger a NULL dereference
through an IPv6 rpfilter lookup:
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000000
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: rpfilter_mt (net/ipv6/netfilter/ip6t_rpfilter.c:75)
Call Trace:
ip6t_do_table (net/ipv6/netfilter/ip6_tables.c:316)
nf_hook_slow (net/netfilter/core.c:619)
ipv6_rcv (net/ipv6/ip6_input.c:351)
__netif_receive_skb_one_core (net/core/dev.c:6216)
process_backlog (net/core/dev.c:6680)
__napi_poll (net/core/dev.c:7739)
net_rx_action (net/core/dev.c:7959)
handle_softirqs (kernel/softirq.c:622)
do_softirq.part.0 (kernel/softirq.c:523)
__local_bh_enable_ip (kernel/softirq.c:450)
__dev_queue_xmit (net/core/dev.c:4913)
packet_sendmsg (net/packet/af_packet.c:3139)
__sys_sendto (net/socket.c:2252)
__x64_sys_sendto (net/socket.c:2259)
do_syscall_64 (arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
Kernel panic - not syncing: Fatal exception in interrupt
Reject routes without an inet6_dev immediately after lookup. Such routes
are not eligible for reverse-path filtering, and the check protects all
later rt6i_idev dereferences.
Fixes: e26f9a480f ("netfilter: add ipv6 reverse path filter match")
Reported-by: co+459f67f4d8af8ce6@bugs.sh
Closes: https://lore.kernel.org/all/VtWUkE8QzJt5CroTj2V2v3ZQ0gwbXZ7nq7I3@bugs.sh/
Suggested-by: Florian Westphal <fw@strlen.de>
Assisted-by: Claude:gpt-5
Cc: stable@vger.kernel.org
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We must serialize the release notifier and the config netlink function.
A concurrent thread can issue close() which can call the release function
while unrelated socket processes UNBIND request for same portid:
Oops: general protection fault, [..]
RIP: 0010:__instance_destroy+0x60/0x210 [nfnetlink_queue]
Call Trace:
nfqnl_recv_config+0x9b0/0xdc0 [nfnetlink_queue]
nfnetlink_rcv_msg+0x7c2/0xeb0
? __pfx_nfnetlink_rcv_msg+0x10/0x10
After this, parallel UNBIND and URELEASE events are impossible.
This change isn't nice, but its the shortest fix given instances
are not refcounted and the nfnetlink config callback drops the
rcu read lock early due to need for sleeping allocations.
Fixes: 7af4cc3fa1 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
flow_offload_work_del() sets NF_FLOW_HW_DEAD before the work handler
clears NF_FLOW_HW_PENDING. Once a flow is both HW_DYING and HW_DEAD, a
concurrent garbage collection pass can remove it and schedule it for RCU
freeing.
The offload worker holds neither an RCU read lock nor a reference to the
flow. If it is preempted after publishing HW_DEAD, the RCU callback can
free the flow before the worker resumes and clears HW_PENDING, resulting
in a use-after-free.
Move HW_DEAD publication to the common worker epilogue after the pending
bit is cleared, making it the final flow access by destroy work. Order all
preceding flow accesses before publishing the bit that allows garbage
collection to free the object.
Fixes: 2c8897953f ("netfilter: flowtable: Add pending bit for offload work")
Assisted-by: Codex:gpt-5
Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Until v7.0, GPIO hogs inherited the DT node name when no line-name
property was specified. This was implemented as a fallback in
of_parse_own_gpio().
Commit d1d564ec49 ("gpio: move hogs into GPIO core") moved hog parsing
into the GPIO core and removed this fallback.
Consequently, GPIO hogs without a line-name property are now displayed
with a ? in /sys/kernel/debug/gpio. Restore the old fallback.
Fixes: d1d564ec49 ("gpio: move hogs into GPIO core")
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260917153712.134367-1-linux@fw-web.de
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
init_mount_tree() mounts the mutable rootfs on top of nullfs via
LOCK_MOUNT_EXACT(). That declares a pinned mountpoint with a cleanup
attribute in the scope of the whole function so the nullfs root inode
lock and namespace_sem are only dropped when init_mount_tree() returns.
This became a problem when the private nullfs instance for kthreads was
added. kern_mount() allocates a new superblock and alloc_super() takes
the new s_umount with SINGLE_DEPTH_NESTING and then shrinker_mutex via
shrinker_alloc(). Doing that with namespace_sem held teaches lockdep the
dependency
namespace_sem -> s_umount/1 -> shrinker_mutex
With CONFIG_SHRINKER_DEBUG shrinker_debugfs_rename() takes the debugfs
directory inode lock under shrinker_mutex every time a block device is
mounted and lock_mount_exact() takes namespace_sem under the inode lock
of the mountpoint for every mount. So mounting anything on debugfs,
e.g. the tracefs automount on /sys/kernel/debug/tracing, closes the
cycle:
WARNING: possible circular locking dependency detected
7.3.0-rc3+ #17 Not tainted
------------------------------------------------------
rasdaemon/4449 is trying to acquire lock:
(namespace_sem){++++}-{4:4}, at: lock_mount_exact+0x4c/0x308
but task is already holding lock:
(&sb->s_type->i_mutex_key#17){++++}-{4:4}, at: lock_mount_exact+0x3c/0x308
which lock already depends on the new lock.
...
Chain exists of:
namespace_sem --> shrinker_mutex --> &sb->s_type->i_mutex_key#17
This can't actually deadlock. init_mount_tree() runs single-threaded
during early boot before any other task exists and nothing allocates a
superblock under namespace_sem after that. But lockdep can't know that
and disables itself for the rest of the boot.
Move mounting the rootfs on top of nullfs into a helper so the locks
are dropped when it returns.
Fixes: 32750c77e8 ("fs: start all kthreads in nullfs")
Reported-by: Zenghui Yu <yuzenghui@huawei.com>
Closes: https://lore.kernel.org/15174353-3f4a-a1ca-5bd1-ea2a4c77828e@huawei.com
Link: https://patch.msgid.link/20260917-atemtechnik-bleichen-befassen-9a57db01baf0@brauner
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
dissolve_free_hugetlb_folio() doesn't check
hstate_is_gigantic_no_runtime(h) though remove_hugetlb_folio()/
update_and_free_hugetlb_folio() silently bail for such folios, so it frees
a still-listed folio and, on vmemmap restore failure, the
add_hugetlb_folio() rollback corrupts the free list.
Link: https://lore.kernel.org/20260823044118.1097121-2-xialonglong2025@163.com
Fixes: 6eb4e88a6d ("hugetlb: create remove_hugetlb_page() to separate functionality")
Signed-off-by: Longlong Xia <xialonglong@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Assisted-by: Codex:gpt-5.6-sol
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
fib_select_multipath() compares nexthop_nh->nh_saddr against the flow
source address with no lock held, while fib_info_update_nhc_saddr()
stores a new value from another CPU as soon as the preferred source
address of the egress device changes.
Commit 195374d893 ("ipv4: fib: annotate races around nh->nh_saddr_genid
and nh->nh_saddr") added WRITE_ONCE() on the store side and READ_ONCE()
in fib_result_prefsrc() after syzbot reported
BUG: KCSAN: data-race in fib_select_path / fib_select_path
but it only covered that reader. fib_select_multipath(), reached from
fib_select_path(), is a second lockless reader of nh->nh_saddr and was
left bare.
Moreover, nh_saddr is only meaningful when nh_saddr_genid matches
dev_addr_genid, as established by commit 436c3b66ec ("ipv4: Invalidate
nexthop cache nh_saddr more correctly."). fib_select_multipath()
skips that validation, so it can score a nexthop using a stale source
address and skew the ECMP selection.
Annotate both reads with READ_ONCE() and refresh the cached source
address via fib_info_update_nhc_saddr() when the genid does not match,
mirroring fib_result_prefsrc().
Fixes: 32607a332c ("ipv4: prefer multipath nexthop that matches source address")
Signed-off-by: Linkui Xiao <xiaolinkui@kylinos.cn>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260916125316.988044-1-xiaolinkui@126.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
txgbe_fdir_filter_restore() reprograms every filter from
txgbe->fdir_filter_list after a reset. It extracts the ring part of
filter->action with ethtool_get_flow_spec_ring() and maps it onto a
PF rx ring, silently dropping the VF part of the cookie that
txgbe_add_ethtool_fdir_entry() stores there (input->action =
fsp->ring_cookie).
For a rule directed at a VF, restore therefore reprograms the filter
to the PF queue with the same ring index: after any down/up or
txgbe_reinit_locked(), traffic matching the rule is steered to the
PF instead of the VF.
Handle VF rules the same way txgbe_add_ethtool_fdir_entry() does:
validate vf against wx->num_vfs and ring against
wx->num_rx_queues_per_pool, and map the ring onto the absolute
queue index ((vf - 1) * wx->num_rx_queues_per_pool) + ring.
Fixes: 7a91722e0d ("net: txgbe: Support the FDIR rules assigned to VFs")
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Yunfei <zhangyunfei1@kylinos.cn>
Link: https://patch.msgid.link/20260911091123.798931-1-zhangyunfei1@kylinos.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
__vsock_net_mode_string() returns success without updating new_mode when
the transfer length is zero. Its caller then reads the uninitialized enum
and may permanently store a stack-derived value in the write-once child
mode.
Return before calling __vsock_net_mode_string() when *lenp is zero so
that the helper is never invoked with nothing to parse and new_mode is
never read uninitialized. This also prevents an empty write from
locking the current mode.
Fixes: eafb64f40c ("vsock: add netns to vsock core")
Cc: stable@vger.kernel.org
Reviewed-by: Luigi Leonardi <leonardi@redhat.com>
Signed-off-by: Aldo Ariel Panzardo <qwe.aldo@gmail.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260915173050.3176344-1-qwe.aldo@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drm/i915 fixes for 7.3-rc4:
- Revert a commit touching registers that don't necessarily exist
- Check for negative numbers before passing to BIT()
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patch.msgid.link/3f86e0ede95fb3d52053934ac43c5271812428f5@intel.com
xe_mmio_gem issues around fault handler and destroy path.
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Merge tag 'drm-xe-fixes-2026-09-17' of https://gitlab.freedesktop.org/drm/xe/kernel into drm-fixes
Couple shrinker related fixes plus a series of patches fixing several
xe_mmio_gem issues around fault handler and destroy path.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patch.msgid.link/aqvoKaPuLLPBGayA@intel.com
CO-RE relocation of an ldimm64 instruction operates on two instruction
slots. A malformed BPF ELF can end a function after the first slot and
attach a CO-RE relocation to it. libbpf allocates the instruction array
according to the function symbol size, so the shared relocation code would
then access beyond the allocation.
Reject a terminal ldimm64 in libbpf's relocation loop, where the program
length is available, before resolving or applying the relocation. Both
resolved and unresolved relocations validate the absent second slot, and
unresolved relocation poisoning would additionally write past the array.
The in-kernel caller is protected by the verifier's early instruction-stream
check before it applies CO-RE relocations.
Fixes: eacaaed784 ("libbpf: Implement enum value-based CO-RE relocations")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/20260914140852.03DA21F0089B@smtp.kernel.org
Link: https://patch.msgid.link/20260917233222.2542500-11-memxor@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Add a verifier test which retains a map value from an outer callback and
then acquires a lock through an inner callback value before attempting to
release the outer callback value. Both values can denote different elements,
so the verifier must reject the mismatched unlock.
Also exercise callbacks reached through two inner-map lookups. The lookup
results share inner_map_meta but may refer to different one-element arrays,
so their callback values must retain distinct lock identities.
Extend the existing spin_lock failure table and reuse its array and
inner-map fixtures to keep these cases alongside the other lock identity
tests. Update the nested callback reference-leak expectation for the extra
callback value ID.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://patch.msgid.link/20260917233222.2542500-10-memxor@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
