A load-acquire from an arena pointer is converted to BPF_PROBE_ATOMIC and
gets an exception table entry, but the entry is filled in as if it were a
store, since populate_extable() decides based on instruction class alone
and a load-acquire is of BPF_STX class:
if (BPF_CLASS(insn->code) == BPF_LDX) {
arena_reg = reg2pt_regs[src_reg];
fixup_reg = reg2pt_regs[dst_reg];
} else {
arena_reg = reg2pt_regs[dst_reg];
fixup_reg = DONT_CLEAR;
}
For a load-acquire dst_reg holds the loaded value and src_reg holds the
address, so both assignments in the else branch are wrong. On a fault
over an unmapped arena page ex_handler_bpf() then:
- computes the reported address from the value register instead
of the address register
- reports the access as a WRITE, since it derives the direction
from fixup_reg == DONT_CLEAR
- leaves dst_reg untouched, so the program continues with a stale
value instead of the 0 that BPF_PROBE_* loads deliver
The access itself is emitted correctly, emit_atomic_ld_st_index() uses
src_reg as the address, so this is a broken probe contract and a wrong
diagnostic rather than a memory safety issue.
Use bpf_atomic_is_load_acq() helper so a load-acquire takes the load path.
Fixes: 5341c9a4d8 ("bpf, x86: Support load-acquire and store-release instructions")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260806201047.333389-3-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
A load-acquire is the only BPF_STX class instruction that reads from
src_reg into dst_reg, that is, it has the operand roles of a BPF_LDX.
JIT code which tells loads from stores apart by instruction class alone
has to special case it, for example when deciding which register holds
the faulting address and which one to clear from an exception handler.
riscv64 already does so, open coded as a bare insn->imm test. Add a
bpf_atomic_is_load_acq() helper and convert riscv64 over to it, so that
the x86-64 and arm64 JITs can use the same helper in subsequent patches.
Unlike bpf_atomic_is_load_store(), which presumes that its argument is
already known to be a BPF_ATOMIC instruction, the new helper is called
from code which still sees all instruction classes, so it checks class
and mode itself.
Also, move bpf_atomic_is_load_store() to filter.h next to BPF_ATOMIC_OP,
so that both helpers stay together. No functional change intended.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260806201047.333389-2-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
A BPF_LOAD_ACQ is not rewritten to a BPF_PROBE_MEM load by the verifier,
unlike a regular BPF_LDX, so the JIT emits a plain load with no exception
table entry and a fault panics the kernel instead of being handled.
Reject the source pointer types that a BPF_LDX would have had that fault
protection applied to, i.e. the ones bpf_convert_ctx_accesses() turns
into BPF_PROBE_MEM: a bare PTR_TO_BTF_ID, PTR_TO_BTF_ID | PTR_UNTRUSTED,
PTR_TO_BTF_ID | MEM_ALLOC | PTR_UNTRUSTED and PTR_TO_MEM | MEM_RDONLY |
PTR_UNTRUSTED.
This is reachable e.g. by loading ->mm out of a trusted task_struct
yields an untrusted pointer to mm_struct, and it is NULL for a kernel
thread:
[...]
SEC("tp_btf/sched_switch")
int BPF_PROG(demo, bool preempt, struct task_struct *prev,
struct task_struct *next)
{
struct mm_struct *mm = next->mm; /* untrusted */
out_ldx = (__u64)mm->pgd; /* BPF_LDX */
out_acq = load_acquire(&mm->pgd); /* BPF_LOAD_ACQ */
return 0;
}
[...]
Both dereference the same pointer, but only the BPF_LDX is protected
(x86-64 JIT, jump targets shown prog-relative):
[...]
; out_ldx = (__u64)mm->pgd;
17: movq $-10485760, %r10
1e: movq %rsi, %r11
21: addq $184, %r11
28: subq %r10, %r11
2b: movabsq $140737498841088, %r10
35: cmpq %r10, %r11
38: ja 0x3e <-- kernel addr?
3a: xorl %edi, %edi <-- no: dst = 0, skip the load
3c: jmp 0x45
3e: movq 184(%rsi), %rdi <-- yes: load + extable entry
[...]
; load_acquire(&mm->pgd)
53: movq %rsi, %rdi
56: movq 184(%rdi), %rax <-- no check, no extable entry
[...]
Note that BPF_PROBE_MEM is not visible in a bpftool xlated dump, as
bpf_insn_prepare_dump() rewrites it back to BPF_MEM.
A PTR_TRUSTED pointer is deliberately not on the list. Such a load is
not converted either, but it does not need to be, since the pointer is
guaranteed live, so load-acquire from it stays allowed.
The check is gated on BPF_LOAD_ACQ so that atomic RMW and store-release
error messages are unchanged; writes (RMW / store-release) to such
pointers are already rejected elsewhere, so only load-acquire needs this.
Fixes: 880442305a ("bpf: Introduce load-acquire and store-release instructions")
Reported-by: STAR Labs SG <info@starlabs.sg>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260806201047.333389-1-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Add __must_hold() attribute to vfio_ccw_sch_quiesce() in order to let
clang's context analysis know that sch->lock must be held on function
entry. This can also be easily verified when inspecting the function.
Without this annotation this leads to a valid warning when context
analysis is enabled:
drivers/s390/cio/vfio_ccw_drv.c:55:9: warning:
expecting spinlock 'sch->lock' to be held at start of each loop [-Wthread-safety-analysis]
55 | ret = cio_cancel_halt_clear(sch, &iretry);
| ^
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
[borntraeger@linux.ibm.com: fix spurious ;]
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
When a user unbinds an MSC and that MSC is the only MSC left for a
component then the corresponding mpam_component will be freed. If the user
then goes on to read the schemata file in the resctrl filesystem then the
mpam_component will be accessed from resctrl_arch_get_config() leading to a
use after free.
As the MPAM driver is not a module the unbind sysfs interface is the only
way to trigger the remove. Instead of dealing with the complexity of
allowing some unused MSC to unbind just remove the unbind sysfs interface.
Fixes: f04046f257 ("arm_mpam: Add probe/remove for mpam msc driver and kbuild boiler plate")
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
If a user unbinds an MSC after mpam_disable() has been run in response
to an error interrupt then a dereference of a NULL pointer occurs as
mpam_disable() sets the drvdata to NULL. Add an early return to the driver
remove callback to avoid this.
Fixes: f04046f257 ("arm_mpam: Add probe/remove for mpam msc driver and kbuild boiler plate")
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
PERF_SAMPLE_BRANCH_HW_INDEX is supported by BRBE so hw_id is passed to
userspace, but it's never set by the BRBE driver. Zero initialize it as
it should be according to the docs:
* For the architectures whose raw branch records are
* already stored in age order, the hw_idx should be 0.
It's probably too risky to remove PERF_SAMPLE_BRANCH_HW_INDEX from BRBE
now in case anyone is setting it and reading the value, but zero
initializing the whole struct also protects against the same issue with
new fields that are added in the future.
Fixes: 58074a0fce ("perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)")
Signed-off-by: James Clark <james.clark@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
The linear aliases of the kernel text and rodata are also mapped
read-only in the linear map. Given that the contents of these regions
are mostly identical to the version in the loadable image, mapping them
read-only and leaving their contents visible is a reasonable hardening
measure.
Data and bss, however, are now also mapped read-only but the contents of
these regions are more likely to contain data that we'd rather not leak.
So let's unmap these entirely in the linear map when the kernel is
running normally.
When going into hibernation or waking up from it, these regions need to
be mapped, so map the region initially, and toggle the valid bit so
map/unmap the region as needed.
Doing so is required because pages covering the kernel image are marked
as PageReserved, and therefore disregarded for snapshotting by the
hibernate logic unless they are mapped.
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Liz Prucka <lizprucka@google.com>
Cc: Seth Jenkins <sethjenkins@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Some of fields are redundant in etmv4_save_state and never used:
ss_status => trcsscsr
seq_state => trcseqstr
cntr_val => trccntvr
vinst_ctrl => trcvictlr
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260725113645.57519-13-yeoreum.yun@arm.com
In the perf enable path, there are missing cases where
cscfg_csdev_disable_active_config() is not called:
- Branch broadcast is selected but not supported by the hardware
- etm4_enable_hw() fails
This can lead to a leak of config_desc->active_cnt.
Fix this by properly calling cscfg_csdev_disable_active_config()
in these error paths.
Fixes: 810ac401db ("coresight: etm4x: Add complex configuration handlers to etmv4")
Suggested-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260725113645.57519-6-yeoreum.yun@arm.com
If etm4_enable_sysfs() fails in cscfg_csdev_enable_active_config(),
the trace ID may be leaked because it is not released.
To address this, call etm4_release_trace_id() when etm4_enable_sysfs()
fails in cscfg_csdev_enable_active_config().
Fixes: 7ebd0ec6cf ("coresight: configfs: Allow configfs to activate configuration")
Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260725113645.57519-4-yeoreum.yun@arm.com
According to IHI006H Embedded Trace Macrocell Architecture
Specification[0], TRCSEQEVR<n> is implemented only when
TRCIDR5.NUMSEQSTATE is 0b100, in which case n ranges from 0 to 2;
otherwise, TRCIDR5.NUMSEQSTATE is 0b000.
IOW, the number of usage in the initialisation or setting
TRCSEQEVR<n> with drvdata->nrseqstate - 1 in the loop could make
underflow issue when TRCIDR5.NUMSEQSTATE is 0b000.
Therefore, introduce nr_seq_ctrls field and untie it from nrseqstate.
As part of this introduce ETM_MAX_SEQ_TRANSITIONS macro and
apply nr_seq_ctrls and above macro to TRCSEQEVR<n> relevant fields setup.
Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
Fixes: 2e1cdfe184 ("coresight-etm4x: Adding CoreSight ETM4x driver")
Suggested-by: Leo Yan <leo.yan@arm.com>
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260725113645.57519-3-yeoreum.yun@arm.com
According to Embedded Trace Macrocell Architecture Specification
ETMv4.0 to ETM4.6 [0], TRCSSPCICR<n> is present only if all of
the following are true:
- TRCIDR4.NUMSSCC > n.
- TRCIDR4.NUMPC > 0b0000.
- TRCSSCSR<n>.PC == 0b1.
Comment for etm4x_sspcicrn_present() is align with the specification.
However, the check should use drvdata->nr_pe_cmp to check TRCIDR4.NUMPC
not nr_pe.
Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
Fixes: f6a18f354c ("coresight: etm4x: Handle access to TRCSSPCICRn")
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260725113645.57519-2-yeoreum.yun@arm.com
hisi_ptt_trace_start() clears all four trace buffers before enabling
tracing.
This is unnecessary. On trace stop, hisi_ptt_update_aux() copies only
the number of bytes reported in HISI_PTT_TRACE_WR_STS. On buffer-full
interrupts, it copies a full completed buffer. In both cases the driver
only consumes data written by hardware.
Remove the buffer clearing from the trace start path.
Signed-off-by: Sanman Pradhan <psanman@juniper.net>
Reviewed-by: Yicong Yang <yangyccccc@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260414172451.14331-3-sanman.pradhan@hpe.com
hisi_ptt_wait_dma_reset_done() discards the return value of
readl_poll_timeout_atomic(). If the DMA engine does not complete its
reset within the timeout, hisi_ptt_trace_start() proceeds to start
tracing regardless.
Return a bool from hisi_ptt_wait_dma_reset_done(), consistent with the
other wait helpers in this driver. On timeout, log an error, de-assert
the reset bit, and return -ETIMEDOUT. Move ctrl->started to the
successful path so a failed start does not leave the trace marked as
active.
Fixes: ff0de066b4 ("hwtracing: hisi_ptt: Add trace function support for HiSilicon PCIe Tune and Trace device")
Cc: stable@vger.kernel.org
Signed-off-by: Sanman Pradhan <psanman@juniper.net>
Reviewed-by: Sizhe Liu <liusizhe5@huawei.com>
Reviewed-by: Yicong Yang <yangyccccc@gmail.com>
Tested-by: Sizhe Liu <liusizhe5@huawei.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260414172451.14331-2-sanman.pradhan@hpe.com
Yicong left Huawei a while back so drop both of our entries and add one for
Sizhe Liu who will be looking after this code going forwards.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Sizhe Liu <liusizhe5@huawei.com>
Acked-by: Jie Zhan <zhanjie9@hisilicon.com>
Acked-by: Yicong Yang <yangyccccc@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260416094219.25258-1-Jonathan.Cameron@huawei.com
The cntr_val_show() function was intended to print the values of all
counters using a loop. However, due to a buffer overwrite issue with
sprintf(), it effectively only displayed the value of the last counter.
The companion function, cntr_val_store(), allows users to modify a
specific counter selected by 'cntr_idx'. To maintain consistency
between read and write operations and to align with the ETM4x driver
behavior, modify cntr_val_show() to report only the value of the
currently selected counter.
This change removes the loop and the "counter %d:" prefix, printing
only the hexadecimal value. It also adopts sysfs_emit() for standard
sysfs output formatting.
Fixes: a939fc5a71 ("coresight-etm: add CoreSight ETM/PTM driver")
Cc: stable@vger.kernel.org
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20251202082613.3265761-1-visitorckw@gmail.com
raid1_takeover() sets conf->array_frozen = 1 on the newly-allocated
r1conf and nothing ever clears it, so every I/O to the array stalls
permanently once _wait_barrier() sees it stuck at 1.
This used to be harmless: level_store() called mddev_resume() right
after pers->run(), which called raid1_quiesce(mddev, 0) and cleared
array_frozen back to 0 regardless of what raid1_takeover() set. Commit
b39f35ebe8 ("md: don't quiesce in mddev_suspend()") removed that
quiesce(mddev, 0) call, so the pre-set now sticks.
setup_conf() already zero-initializes the new r1conf via kzalloc, so
just don't set array_frozen here.
Same class of bug as commit 892da88d1c ("md/raid10: fix a
'conf->barrier' leakage in raid10_takeover()"), also triggered by
b39f35ebe8.
Fixes: b39f35ebe8 ("md: don't quiesce in mddev_suspend()")
Link: https://issues.redhat.com/browse/RHEL-191802
Signed-off-by: Bruce Johnston <bjohnsto@redhat.com>
Link: https://patch.msgid.link/20260803180240.1177104-1-bjohnsto@redhat.com
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Inline headset buttons (play/pause, volume up/down) are unresponsive on
the Lenovo Yoga Pro 7 14ASP10. Enable headset jack handling by chaining
alc_fixup_headset_jack to the existing bass speaker fixup for this model.
Signed-off-by: Marco Giunta <marco_giunta@outlook.it>
Link: https://patch.msgid.link/IA1PR19MB77127DE4BC25300BAD284E30FCD22@IA1PR19MB7712.namprd19.prod.outlook.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The HP Spectre x360 2-in-1 Laptop 16-aa0xxx with PCI subsystem ID
0x103c:0x8c17 only gets the CS35L41 amplifier setup from
ALC287_FIXUP_CS35L41_I2C_2, so the speaker-mute and mic-mute keyboard
LEDs do not work.
Use ALC245_FIXUP_HP_SPECTRE_X360_16_AA0XXX like subsystem ID 0x8c16 so
the mute LEDs work.
Tested on HP Spectre x360 2-in-1 Laptop 16-aa0xxx.
Signed-off-by: Shang En Sim <sim@shangen.org>
Link: https://patch.msgid.link/20260807055139.58707-1-sim@shangen.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
blk_stack_limits() uses min_not_zero() when stacking discard limits.
Thus an array containing devices with different discard capabilities can
expose discard support as long as at least one member has a non-zero
discard limit.
raid0 and raid10 use md_submit_discard_bio() to submit a discard bio to
each member covered by the request. The helper currently also submits
bios to members whose max_discard_sectors is zero. The block layer
completes these bios with BLK_STS_NOTSUPP, and bio chaining propagates
that status to the original discard request.
Discard is optional, so skip members which do not support it. Members that
do support discard continue to receive their portion of the request.
Signed-off-by: Wale Zhang <wale.zhang.ftd@gmail.com>
Link: https://patch.msgid.link/20260731074729.1885314-1-wale.zhang.ftd@gmail.com
Signed-off-by: Yu Kuai <yukuai@fygo.io>
The recent fix for sticky mixer volumes caused regressions of M-audio
Fast Track Ultra device, where the mixer state is kept to the default
value.
Add the quirk entries to tolerate the broken mixer behavior. As the
device is known to work in the implicit feedback mode, explicitly
enable the implicit feedback mode, too.
Since there are two FTU models that are almost identical, both entries
are added in this patch (0763:2080 and 0763:2081).
Fixes: 86aa1ea1f1 ("ALSA: usb-audio: Do not expose sticky mixers")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1273166
Link: https://patch.msgid.link/20260807083418.1712585-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Convert TI IODELAY controller from text to DT schema. Document child
properties missing from text bindings for proper validation.
Signed-off-by: Bhargav Joshi <j.bhargav.u@gmail.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>
When sync_request() reports a skipped region (*skipped == 1),
md_do_sync()'s main loop advances the cursor and takes an early
continue:
j += sectors;
...
if (last_check + window > io_sectors || j == max_sectors)
continue;
If the personality returns a small span per call (raid10 recovery
returns only 128 sectors), syncing a large, mostly clean array iterates
this branch an enormous number of times without ever yielding the CPU.
On a non-preemptive kernel the resync thread then trips the soft-lockup
watchdog:
watchdog: BUG: soft lockup - CPU#149 stuck for 313s! [mdX_resync]
md_bitmap_start_sync+0x6f/0xe0
raid10_sync_request+0x2c9/0x1530 [raid10]
md_do_sync+0x810/0x1030
md_thread+0xa7/0x150
Add a cond_resched(). This does not reduce the wasted iterations; the
excessive iteration count is a raid10 problem addressed separately.
Signed-off-by: Yunye Zhao <yunye.zhao@linux.alibaba.com>
Link: https://patch.msgid.link/20260723135535.101995-3-yunye.zhao@linux.alibaba.com
Signed-off-by: Yu Kuai <yukuai@fygo.io>
With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone()
initializes struct pages early in boot to satisfy an allocation.
With a large CMA reservation in place, the ranges deferred_init_memmap()
finds may not add up to the allocation it was asked for, and the function
ends up initializing the memory map of the entire zone and still falls
short.
That is fine in itself: the function accounts for it and leaves the
caller to decide whether it now has enough memory.
However, the update of pgdat->first_deferred_pfn that tracks where
uninitialized memory map starts could overflow.
If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and
some deferred struct pages were initialized, pgdat->first_deferred_pfn
would point past the end of the node's memory.
deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and
hits a BUG_ON(), because it expects a pfn within its node.
For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
and CONFIG_CMA=y using the following qemu command line
qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \
-append "nokaslr cma=4768M@0x100000000"
the kernel panics:
kernel BUG at mm/mm_init.c:2131!
CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1
RIP: 0010:deferred_init_memmap+0x1b8/0x1c0
RAX: 0000000000236000 R13: 0000000000238000
Call Trace:
kthread+0xdf/0x120
ret_from_fork+0x187/0x250
Make sure that the update of pgdta->first_deferred_pfn does not overflow
when the entire zone's (and therefore node's) memory map is initialized.
Fixes: 3acb913c9d ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()")
Cc: stable@vger.kernel.org
Assisted-by: Kiro:claude-opus-5
Signed-off-by: Alexander Graf <graf@amazon.com>
Link: https://patch.msgid.link/20260807031243.87904-1-graf@amazon.com
[rppt: massaged the changelog]
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Explicitly clear role.invalid when deriving a child shadow page's role from
its parent to harden against bugs elsewhere in KVM, as violating KVM's
invariant that invalid pages are NOT on the list of active MMU pages leads
to use-after-free due to __kvm_mmu_prepare_zap_page() using list_add()
instead of list_move() when processing an invalid shadow page, i.e. makes a
bad situation far worse.
Yell loudly if the parent is invalid, as it means KVM has missed a validity
check, i.e. KVM is attempting to map memory using an invalid/obsolete root,
but continue on as the child is otherwise still a valid shadow page.
==================================================================
BUG: KASAN: slab-use-after-free in __kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]
Write of size 8 at addr ff11000153dd1368 by task repro/853
CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
<TASK>
dump_stack_lvl+0x4b/0x70
print_report+0x153/0x49c
kasan_report+0xbc/0xf0
__kvm_mmu_get_shadow_page+0x1817/0x1860 [kvm]
mmu_alloc_root+0x141/0x320 [kvm]
kvm_mmu_load+0x612/0x20f0 [kvm]
kvm_arch_vcpu_ioctl_run+0x3dd5/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]
__x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
Allocated by task 853:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x5f/0x70
kmem_cache_alloc_noprof+0xfe/0x2e0
__kvm_mmu_topup_memory_cache+0x135/0x530 [kvm]
paging64_page_fault+0x318/0x1e30 [kvm]
kvm_mmu_do_page_fault+0x21d/0x630 [kvm]
kvm_mmu_page_fault+0x18c/0x17b0 [kvm]
kvm_arch_vcpu_ioctl_run+0x1f35/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]
__x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Freed by task 853:
kasan_save_stack+0x20/0x40
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x43/0x70
kmem_cache_free+0xe2/0x400
kvm_mmu_commit_zap_page.part.0+0x1e2/0x310 [kvm]
kvm_mmu_free_roots+0x283/0x560 [kvm]
kvm_arch_vcpu_ioctl_run+0x33c8/0x6150 [kvm]
kvm_vcpu_ioctl+0x5e4/0x10d0 [kvm]
__x64_sys_ioctl+0x131/0x1b0
do_syscall_64+0x67/0x5f0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Fixes: a770f6f28b ("KVM: MMU: Inherit a shadow page's guest level count from vcpu setup")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit fe6a19d40c ("md/md-bitmap: merge md_bitmap_start_sync() into
bitmap_operations") converted still_degraded from int to bool, but
inverted the assignment in the loop that checks whether the array will
still be degraded after the current device is recovered:
"still_degraded = 1" became "still_degraded = false".
As a result, recovering a device while another mirror is still missing
calls md_bitmap_start_sync() with degraded == false, which clears bitmap
bits that the still-missing device needs. When that device is re-added,
its bitmap-based recovery finds the bits already cleared and skips every
region written while the array was degraded, so it is marked In_sync
while holding stale data: silent corruption.
Reproducer (raid10 near=2, 4 disks, internal bitmap):
- fail and remove one disk of each mirror pair
- write to the degraded array
- re-add both disks and let recovery finish
- "check" reports mismatch_cnt=262272 after 256 MiB of degraded
writes and file contents differ; the second disk's "recovery"
completes in milliseconds because everything is skipped
The same conversion in raid1 got it right (still_degraded = true).
Restore the correct value.
Fixes: fe6a19d40c ("md/md-bitmap: merge md_bitmap_start_sync() into bitmap_operations")
Cc: stable@vger.kernel.org
Signed-off-by: Yunye Zhao <yunye.zhao@linux.alibaba.com>
Reviewed-by: Mykola Marzhan <mykola@meshstor.io>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Yu Kuai <yukuai@fygo.io>
Link: https://patch.msgid.link/20260723135535.101995-2-yunye.zhao@linux.alibaba.com
Signed-off-by: Yu Kuai <yukuai@fygo.io>
RAID5 maps array sectors through different geometries before and after the
reshape position. During llbitmap reshape, md core cannot account one bio
against both geometries as a single bitmap range, because the old and new
bitmap mappings can cover different chunks.
Split bios that cross reshape_position before md_account_bio(), so the
bitmap only sees ranges that belong to one side of the reshape boundary.
mddev_bio_split_at_reshape_offset() uses bio_submit_split_bioset(), which
submits the remainder immediately and returns the front split bio. If that
front bio later has to wait for reshape, md_handle_request() must not retry
the original bio pointer, because after the split that pointer is the
already-submitted remainder. Track whether the split happened, clear the
temporary BLK_STS_RESOURCE status after the internal clone completion, and
resubmit the front bio directly after the reshape wait. Keep the old
return-false retry path for unsplit bios, where md_handle_request() still
owns the same bio.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-30-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
llbitmap reshape keeps one live bitmap and cannot safely make an
existing bitmap bit cover a smaller data range.
The llbitmap chunksize itself will not shrink when mddev->chunk_sectors
stays the same or grows. However, shrinking mddev->chunk_sectors shrinks
sectors_per_chunk used by raid5_bitmap_sector_map(). That can shrink the
effective data range covered by each bit across the old and new RAID5
geometry. Reject that reshape while llbitmap is active.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-28-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Teach RAID5 to export exact old and new llbitmap mappings and the
corresponding sync and array sizes for reshape-aware bitmap users.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-27-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Use the shared mddev_bio_split_at_reshape_offset() helper so RAID10
submits only one-side bios to llbitmap during reshape.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-26-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Prepare llbitmap before RAID10 starts growing, checkpoint the bitmap
before advancing reshape_position, finish the llbitmap geometry update
when reshape completes, and export the old and new tracked sizes.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-25-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
llbitmap reshape keeps one live bitmap and cannot safely make an
existing bitmap bit cover a smaller data range.
The llbitmap chunksize itself will not shrink when mddev->chunk_sectors
stays the same or grows. However, shrinking mddev->chunk_sectors can
shrink the effective data range covered by each bit for the RAID10
reshape geometry. Reject that reshape while llbitmap is active.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-24-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
llbitmap_state_machine() can be called with an end bit beyond
llbitmap->chunks. In particular, llbitmap_cond_end_sync() passes
sector >> chunkshift, and sector can reach the tracked boundary
exactly.
Clamp the state-machine range to llbitmap->chunks so it cannot walk
past the tracked bitmap.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-23-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Merge checkpointed old llbitmap state forward as reshape_position advances
and record the checkpoint remap through reshape_mark().
Normal write accounting can run while the reshape thread checkpoints a new
reshape position. llbitmap_reshape_mark() reads old state bytes, merges them
into destination bits, and writes the result back. If llbitmap_start_write()
or llbitmap_start_discard() updates the same state bytes at the same time,
the two read/modify/write paths can overwrite each other and lose the state
from one side.
Serialize only this state-byte race with a rwlock. Normal I/O takes the read
side around llbitmap_state_machine(), after page active references are raised,
so concurrent normal I/O updates still run in parallel. Reshape checkpointing
takes the write side only while merging the checkpointed range, avoiding page
suspension and avoiding a sleeping mutex in the I/O accounting path.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-22-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Reshape progress is tracked by array metadata rather than llbitmap.
Do not let llbitmap skip_sync_blocks() suppress reshape ranges based on
stale bitmap state before the corresponding checkpoint is persisted.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-21-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Teach llbitmap to choose old versus new geometry during reshape and to
encode exact bitmap ranges for the active geometry. This is the mapping
groundwork for checkpoint remapping.
Range preparation now distinguishes writes from discards. Normal writes
must cover every touched bitmap chunk, while discards may only mark fully
covered chunks unwritten. Without this distinction, a discard that starts
or ends inside a chunk can make live data look unwritten after the range
has been mapped and floored.
Reproduce that with a RAID1 llbitmap using 128-sector chunks. A discard
starting halfway into chunk 8 with a 128-sector length changed clean bits
from 16352 to 16350 and unwritten bits from 0 to 2, even though no chunk
was fully discarded. With discard-specific range encoding, both counts
stay unchanged for the same test.
Range preparation also clamps the pre-map range in the same coordinate
space as the incoming IO. RAID5 receives array-sector offsets but tracks
llbitmap sync size in component sectors, so steady-state RAID5 must use
bitmap_array_sectors() before mapping and keep the existing sync-size
clamp after mapping.
Reproduce that with a 4-disk RAID5 llbitmap created --assume-clean. A
write below dev_sectors changed dirty bits from 0 to 512, but a write at
seek=2094080 left the count at 512. With the array-sector pre-map limit,
writing at seek=component_size + 65536 increased dirty bits from 512 to
1024.
Link: https://lore.kernel.org/all/20260726185916.2223460-1-mykola@meshstor.io/
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-20-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Reject reshape when llbitmap still contains NeedSync or Syncing bits.
This keeps reshape from starting until the current llbitmap state has
been reconciled.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-19-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Commit the staged llbitmap geometry when reshape finishes.
When assembling a stopped reshape, md_run() creates the bitmap before
publishing mddev->pers. llbitmap_read_sb() can therefore only initialize
the reshape fields from the old on-disk sync size. Refresh the staged
reshape geometry again from llbitmap_load(), after mddev->pers is
available, and expand the in-memory page controls before replaying bitmap
state.
Reproduce on the old kernel by creating a RAID10 llbitmap with four
active disks and two spares, growing it to six disks, then stopping and
assembling while reshape is still running. The llbitmap chunk count was
32704 before grow, 49056 during reshape, then rolled back to 32704 after
reassemble.
The fixed kernel kept the target geometry across the same stop/reassemble
flow: 65440 chunks before grow, 98160 during reshape, and 98160 after
reassemble.
Link: https://lore.kernel.org/all/20260726185916.2223460-1-mykola@meshstor.io/
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-18-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
Track llbitmap bookkeeping for the target reshape geometry while keeping
a single live bitmap instance.
Add the reshape geometry fields, refresh helper, and update the load and
resize paths to keep the target geometry in sync.
Tested-by: Mykola Marzhan <mykola@meshstor.io>
Link: https://patch.msgid.link/20260802195038.164272-17-yukuai@kernel.org
Signed-off-by: Yu Kuai <yukuai@fygo.io>
