Linux: >> Linux Kernel >> 5.15.194 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
erofs: Fix detection of atomic context
Current check for atomic context is not sufficient as
z_erofs_decompressqueue_endio can be called under rcu lock
from blk_mq_flush_plug_list(). See the stacktrace [1]
In such case we should hand off the decompression work for async
processing rather than trying to do sync decompression in current
context. Patch fixes the detection by checking for
rcu_read_lock_any_held() and while at it use more appropriate
!in_task() check than in_atomic().
Background: Historically erofs would always schedule a kworker for
decompression which would incur the scheduling cost regardless of
the context. But z_erofs_decompressqueue_endio() may not always
be in atomic context and we could actually benefit from doing the
decompression in z_erofs_decompressqueue_endio() if we are in
thread context, for example when running with dm-verity.
This optimization was later added in patch [2] which has shown
improvement in performance benchmarks.
==============================================
[1] Problem stacktrace
[name:core&]BUG: sleeping function called from invalid context at kernel/locking/mutex.c:291
[name:core&]in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1615, name: CpuMonitorServi
[name:core&]preempt_count: 0, expected: 0
[name:core&]RCU nest depth: 1, expected: 0
CPU: 7 PID: 1615 Comm: CpuMonitorServi Tainted: G S W OE 6.1.25-android14-5-maybe-dirty-mainline #1
Hardware name: MT6897 (DT)
Call trace:
dump_backtrace+0x108/0x15c
show_stack+0x20/0x30
dump_stack_lvl+0x6c/0x8c
dump_stack+0x20/0x48
__might_resched+0x1fc/0x308
__might_sleep+0x50/0x88
mutex_lock+0x2c/0x110
z_erofs_decompress_queue+0x11c/0xc10
z_erofs_decompress_kickoff+0x110/0x1a4
z_erofs_decompressqueue_endio+0x154/0x180
bio_endio+0x1b0/0x1d8
__dm_io_complete+0x22c/0x280
clone_endio+0xe4/0x280
bio_endio+0x1b0/0x1d8
blk_update_request+0x138/0x3a4
blk_mq_plug_issue_direct+0xd4/0x19c
blk_mq_flush_plug_list+0x2b0/0x354
__blk_flush_plug+0x110/0x160
blk_finish_plug+0x30/0x4c
read_pages+0x2fc/0x370
page_cache_ra_unbounded+0xa4/0x23c
page_cache_ra_order+0x290/0x320
do_sync_mmap_readahead+0x108/0x2c0
filemap_fault+0x19c/0x52c
__do_fault+0xc4/0x114
handle_mm_fault+0x5b4/0x1168
do_page_fault+0x338/0x4b4
do_translation_fault+0x40/0x60
do_mem_abort+0x60/0xc8
el0_da+0x4c/0xe0
el0t_64_sync_handler+0xd4/0xfc
el0t_64_sync+0x1a0/0x1a4
[2] Link: https://lore.kernel.org/all/20210317035448.13921-1-huangjianan@oppo.com/
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Make it so that a waiting process can be aborted
When sendmsg() creates an rxrpc call, it queues it to wait for a connection
and channel to be assigned and then waits before it can start shovelling
data as the encrypted DATA packet content includes a summary of the
connection parameters.
However, sendmsg() may get interrupted before a connection gets assigned
and further sendmsg() calls will fail with EBUSY until an assignment is
made.
Fix this so that the call can at least be aborted without failing on
EBUSY. We have to be careful here as sendmsg() mustn't be allowed to start
the call timer if the call doesn't yet have a connection assigned as an
oops may follow shortly thereafter.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix memleak due to fentry attach failure
If it fails to attach fentry, the allocated bpf trampoline image will be
left in the system. That can be verified by checking /proc/kallsyms.
This meamleak can be verified by a simple bpf program as follows:
SEC("fentry/trap_init")
int fentry_run()
{
return 0;
}
It will fail to attach trap_init because this function is freed after
kernel init, and then we can find the trampoline image is left in the
system by checking /proc/kallsyms.
$ tail /proc/kallsyms
ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf]
ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf]
$ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'"
[2522] FUNC 'trap_init' type_id=119 linkage=static
$ echo $((6442453466 & 0x7fffffff))
2522
Note that there are two left bpf trampoline images, that is because the
libbpf will fallback to raw tracepoint if -EINVAL is returned.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211_hwsim: Fix possible NULL dereference
In a call to mac80211_hwsim_select_tx_link() the sta pointer might
be NULL, thus need to check that it is not NULL before accessing it.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
orangefs: Fix kmemleak in orangefs_sysfs_init()
When insert and remove the orangefs module, there are kobjects memory
leaked as below:
unreferenced object 0xffff88810f95af00 (size 64):
comm "insmod", pid 783, jiffies 4294813439 (age 65.512s)
hex dump (first 32 bytes):
a0 83 af 01 81 88 ff ff 08 af 95 0f 81 88 ff ff ................
08 af 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000005a6e4dfe>] orangefs_sysfs_init+0x42/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff88810f95ae80 (size 64):
comm "insmod", pid 783, jiffies 4294813439 (age 65.512s)
hex dump (first 32 bytes):
c8 90 0f 02 81 88 ff ff 88 ae 95 0f 81 88 ff ff ................
88 ae 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000001a4841fa>] orangefs_sysfs_init+0xc7/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff88810f95ae00 (size 64):
comm "insmod", pid 783, jiffies 4294813440 (age 65.511s)
hex dump (first 32 bytes):
60 87 a1 00 81 88 ff ff 08 ae 95 0f 81 88 ff ff `...............
08 ae 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000005915e797>] orangefs_sysfs_init+0x12b/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff88810f95ad80 (size 64):
comm "insmod", pid 783, jiffies 4294813440 (age 65.511s)
hex dump (first 32 bytes):
78 90 0f 02 81 88 ff ff 88 ad 95 0f 81 88 ff ff x...............
88 ad 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000007a14eb35>] orangefs_sysfs_init+0x1ac/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff88810f95ac00 (size 64):
comm "insmod", pid 783, jiffies 4294813440 (age 65.531s)
hex dump (first 32 bytes):
e0 ff 67 02 81 88 ff ff 08 ac 95 0f 81 88 ff ff ..g.............
08 ac 95 0f 81 88 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000001f38adcb>] orangefs_sysfs_init+0x291/0x3a0
[<00000000722645ca>] 0xffffffffa02780fe
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix double release compute pasid
If kfd_process_device_init_vm returns failure after vm is converted to
compute vm and vm->pasid set to compute pasid, KFD will not take
pdd->drm_file reference. As a result, drm close file handler maybe
called to release the compute pasid before KFD process destroy worker to
release the same pasid and set vm->pasid to zero, this generates below
WARNING backtrace and NULL pointer access.
Add helper amdgpu_amdkfd_gpuvm_set_vm_pasid and call it at the last step
of kfd_process_device_init_vm, to ensure vm pasid is the original pasid
if acquiring vm failed or is the compute pasid with pdd->drm_file
reference taken to avoid double release same pasid.
amdgpu: Failed to create process VM object
ida_free called for id=32770 which is not allocated.
WARNING: CPU: 57 PID: 72542 at ../lib/idr.c:522 ida_free+0x96/0x140
RIP: 0010:ida_free+0x96/0x140
Call Trace:
amdgpu_pasid_free_delayed+0xe1/0x2a0 [amdgpu]
amdgpu_driver_postclose_kms+0x2d8/0x340 [amdgpu]
drm_file_free.part.13+0x216/0x270 [drm]
drm_close_helper.isra.14+0x60/0x70 [drm]
drm_release+0x6e/0xf0 [drm]
__fput+0xcc/0x280
____fput+0xe/0x20
task_work_run+0x96/0xc0
do_exit+0x3d0/0xc10
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:ida_free+0x76/0x140
Call Trace:
amdgpu_pasid_free_delayed+0xe1/0x2a0 [amdgpu]
amdgpu_driver_postclose_kms+0x2d8/0x340 [amdgpu]
drm_file_free.part.13+0x216/0x270 [drm]
drm_close_helper.isra.14+0x60/0x70 [drm]
drm_release+0x6e/0xf0 [drm]
__fput+0xcc/0x280
____fput+0xe/0x20
task_work_run+0x96/0xc0
do_exit+0x3d0/0xc10
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
mtd: core: fix possible resource leak in init_mtd()
I got the error report while inject fault in init_mtd():
sysfs: cannot create duplicate filename '/devices/virtual/bdi/mtd-0'
Call Trace:
<TASK>
dump_stack_lvl+0x67/0x83
sysfs_warn_dup+0x60/0x70
sysfs_create_dir_ns+0x109/0x120
kobject_add_internal+0xce/0x2f0
kobject_add+0x98/0x110
device_add+0x179/0xc00
device_create_groups_vargs+0xf4/0x100
device_create+0x7b/0xb0
bdi_register_va.part.13+0x58/0x2d0
bdi_register+0x9b/0xb0
init_mtd+0x62/0x171 [mtd]
do_one_initcall+0x6c/0x3c0
do_init_module+0x58/0x222
load_module+0x268e/0x27d0
__do_sys_finit_module+0xd5/0x140
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
kobject_add_internal failed for mtd-0 with -EEXIST, don't try to register
things with the same name in the same directory.
Error registering mtd class or bdi: -17
If init_mtdchar() fails in init_mtd(), mtd_bdi will not be unregistered,
as a result, we can't load the mtd module again, to fix this by calling
bdi_unregister(mtd_bdi) after out_procfs label.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
kprobes: Fix check for probe enabled in kill_kprobe()
In kill_kprobe(), the check whether disarm_kprobe_ftrace() needs to be
called always fails. This is because before that we set the
KPROBE_FLAG_GONE flag for kprobe so that "!kprobe_disabled(p)" is always
false.
The disarm_kprobe_ftrace() call introduced by commit:
0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
to fix the NULL pointer reference problem. When the probe is enabled, if
we do not disarm it, this problem still exists.
Fix it by putting the probe enabled check before setting the
KPROBE_FLAG_GONE flag.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free of new block group that became unused
If a task creates a new block group and that block group becomes unused
before we finish its creation, at btrfs_create_pending_block_groups(),
then when btrfs_mark_bg_unused() is called against the block group, we
assume that the block group is currently in the list of block groups to
reclaim, and we move it out of the list of new block groups and into the
list of unused block groups. This has two consequences:
1) We move it out of the list of new block groups associated to the
current transaction. So the block group creation is not finished and
if we attempt to delete the bg because it's unused, we will not find
the block group item in the extent tree (or the new block group tree),
its device extent items in the device tree etc, resulting in the
deletion to fail due to the missing items;
2) We don't increment the reference count on the block group when we
move it to the list of unused block groups, because we assumed the
block group was on the list of block groups to reclaim, and in that
case it already has the correct reference count. However the block
group was on the list of new block groups, in which case no extra
reference was taken because it's local to the current task. This
later results in doing an extra reference count decrement when
removing the block group from the unused list, eventually leading the
reference count to 0.
This second case was caught when running generic/297 from fstests, which
produced the following assertion failure and stack trace:
[589.559] assertion failed: refcount_read(&block_group->refs) == 1, in fs/btrfs/block-group.c:4299
[589.559] ------------[ cut here ]------------
[589.559] kernel BUG at fs/btrfs/block-group.c:4299!
[589.560] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[589.560] CPU: 8 PID: 2819134 Comm: umount Tainted: G W 6.4.0-rc6-btrfs-next-134+ #1
[589.560] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[589.560] RIP: 0010:btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.561] Code: 68 62 da c0 (...)
[589.561] RSP: 0018:ffffa55a8c3b3d98 EFLAGS: 00010246
[589.561] RAX: 0000000000000058 RBX: ffff8f030d7f2000 RCX: 0000000000000000
[589.562] RDX: 0000000000000000 RSI: ffffffff953f0878 RDI: 00000000ffffffff
[589.562] RBP: ffff8f030d7f2088 R08: 0000000000000000 R09: ffffa55a8c3b3c50
[589.562] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8f05850b4c00
[589.562] R13: ffff8f030d7f2090 R14: ffff8f05850b4cd8 R15: dead000000000100
[589.563] FS: 00007f497fd2e840(0000) GS:ffff8f09dfc00000(0000) knlGS:0000000000000000
[589.563] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[589.563] CR2: 00007f497ff8ec10 CR3: 0000000271472006 CR4: 0000000000370ee0
[589.563] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[589.564] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[589.564] Call Trace:
[589.564] <TASK>
[589.565] ? __die_body+0x1b/0x60
[589.565] ? die+0x39/0x60
[589.565] ? do_trap+0xeb/0x110
[589.565] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.566] ? do_error_trap+0x6a/0x90
[589.566] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.566] ? exc_invalid_op+0x4e/0x70
[589.566] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.567] ? asm_exc_invalid_op+0x16/0x20
[589.567] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.567] ? btrfs_free_block_groups+0x449/0x4a0 [btrfs]
[589.567] close_ctree+0x35d/0x560 [btrfs]
[589.568] ? fsnotify_sb_delete+0x13e/0x1d0
[589.568] ? dispose_list+0x3a/0x50
[589.568] ? evict_inodes+0x151/0x1a0
[589.568] generic_shutdown_super+0x73/0x1a0
[589.569] kill_anon_super+0x14/0x30
[589.569] btrfs_kill_super+0x12/0x20 [btrfs]
[589.569] deactivate_locked
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
mm: fix zswap writeback race condition
The zswap writeback mechanism can cause a race condition resulting in
memory corruption, where a swapped out page gets swapped in with data that
was written to a different page.
The race unfolds like this:
1. a page with data A and swap offset X is stored in zswap
2. page A is removed off the LRU by zpool driver for writeback in
zswap-shrink work, data for A is mapped by zpool driver
3. user space program faults and invalidates page entry A, offset X is
considered free
4. kswapd stores page B at offset X in zswap (zswap could also be
full, if so, page B would then be IOed to X, then skip step 5.)
5. entry A is replaced by B in tree->rbroot, this doesn't affect the
local reference held by zswap-shrink work
6. zswap-shrink work writes back A at X, and frees zswap entry A
7. swapin of slot X brings A in memory instead of B
The fix:
Once the swap page cache has been allocated (case ZSWAP_SWAPCACHE_NEW),
zswap-shrink work just checks that the local zswap_entry reference is
still the same as the one in the tree. If it's not the same it means that
it's either been invalidated or replaced, in both cases the writeback is
aborted because the local entry contains stale data.
Reproducer:
I originally found this by running `stress` overnight to validate my work
on the zswap writeback mechanism, it manifested after hours on my test
machine. The key to make it happen is having zswap writebacks, so
whatever setup pumps /sys/kernel/debug/zswap/written_back_pages should do
the trick.
In order to reproduce this faster on a vm, I setup a system with ~100M of
available memory and a 500M swap file, then running `stress --vm 1
--vm-bytes 300000000 --vm-stride 4000` makes it happen in matter of tens
of minutes. One can speed things up even more by swinging
/sys/module/zswap/parameters/max_pool_percent up and down between, say, 20
and 1; this makes it reproduce in tens of seconds. It's crucial to set
`--vm-stride` to something other than 4096 otherwise `stress` won't
realize that memory has been corrupted because all pages would have the
same data.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-09-15