Description
In the Linux kernel, the following vulnerability has been resolved:
drm/msm: Fix shrinker deadlock
With PROVE_LOCKING on an Snapdragon X1 and VM reclaim pressure, we see:
======================================================
WARNING: possible circular locking dependency detected
7.0.0-debug+ #43 Tainted: G W
------------------------------------------------------
kswapd0/82 is trying to acquire lock:
ffff800080ec3870 (reservation_ww_class_acquire){+.+.}-{0:0}, at: msm_gem_shrinker_scan+0x17c/0x400 [msm]
but task is already holding lock:
ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (fs_reclaim){+.+.}-{0:0}:
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
fs_reclaim_acquire+0xd0/0xf0
dma_resv_lockdep+0x224/0x348
do_one_initcall+0x84/0x5d0
do_initcalls+0x194/0x1d8
kernel_init_freeable+0x128/0x180
kernel_init+0x2c/0x160
ret_from_fork+0x10/0x20
-> #1 (reservation_ww_class_mutex){+.+.}-{4:4}:
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
dma_resv_lockdep+0x1a8/0x348
do_one_initcall+0x84/0x5d0
do_initcalls+0x194/0x1d8
kernel_init_freeable+0x128/0x180
kernel_init+0x2c/0x160
ret_from_fork+0x10/0x20
-> #0 (reservation_ww_class_acquire){+.+.}-{0:0}:
check_prev_add+0x114/0x790
validate_chain+0x594/0x6f0
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
drm_gem_lru_scan+0x1ac/0x440
msm_gem_shrinker_scan+0x17c/0x400 [msm]
do_shrink_slab+0x150/0x4a0
shrink_slab+0x144/0x460
shrink_one+0x9c/0x1b0
shrink_many+0x27c/0x5c0
shrink_node+0x344/0x550
balance_pgdat+0x2c0/0x988
kswapd+0x11c/0x318
kthread+0x10c/0x128
ret_from_fork+0x10/0x20
other info that might help us debug this:
Chain exists of:
reservation_ww_class_acquire --> reservation_ww_class_mutex --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(reservation_ww_class_mutex);
lock(fs_reclaim);
lock(reservation_ww_class_acquire);
*** DEADLOCK ***
1 lock held by kswapd0/82:
#0: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988
stack backtrace:
CPU: 4 UID: 0 PID: 82 Comm: kswapd0 Tainted: G W 7.0.0-debug+ #43 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: LENOVO 21BX0016US/21BX0016US, BIOS N3HET94W (1.66 ) 09/15/2025
Call trace:
show_stack+0x20/0x40 (C)
dump_stack_lvl+0x9c/0xd0
dump_stack+0x18/0x30
print_circular_bug+0x114/0x120
check_noncircular+0x178/0x198
check_prev_add+0x114/0x790
validate_chain+0x594/0x6f0
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
drm_gem_lru_scan+0x1ac/0x440
msm_gem_shrinker_scan+0x17c/0x400 [msm]
do_shrink_slab+0x150/0x4a0
shrink_slab+0x144/0x460
shrink_one+0x9c/0x1b0
shrink_many+0x27c/0x5c0
shrink_node+0x344/0x550
balance_pgdat+0x2c0/0x988
kswapd+0x11c/0x318
kthread+0x10c/0x128
ret_from_fork+0x10/0x20
kswapd0 holding fs_reclaim calls the MSM shrinker, which calls
dma_resv_lock. This in turn acquires fs_reclaim.
Fix this deadlock by using dma_resv_trylock() instead, dropping the
subsequently unused passed wait-wound lock 'ticket'.
Patchwork: https://patchwork.freedesktop.org/patch/723564/
[rob: fixup compile errors, replace lockdep splat with somethin
---truncated---
drm/msm: Fix shrinker deadlock
With PROVE_LOCKING on an Snapdragon X1 and VM reclaim pressure, we see:
======================================================
WARNING: possible circular locking dependency detected
7.0.0-debug+ #43 Tainted: G W
------------------------------------------------------
kswapd0/82 is trying to acquire lock:
ffff800080ec3870 (reservation_ww_class_acquire){+.+.}-{0:0}, at: msm_gem_shrinker_scan+0x17c/0x400 [msm]
but task is already holding lock:
ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (fs_reclaim){+.+.}-{0:0}:
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
fs_reclaim_acquire+0xd0/0xf0
dma_resv_lockdep+0x224/0x348
do_one_initcall+0x84/0x5d0
do_initcalls+0x194/0x1d8
kernel_init_freeable+0x128/0x180
kernel_init+0x2c/0x160
ret_from_fork+0x10/0x20
-> #1 (reservation_ww_class_mutex){+.+.}-{4:4}:
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
dma_resv_lockdep+0x1a8/0x348
do_one_initcall+0x84/0x5d0
do_initcalls+0x194/0x1d8
kernel_init_freeable+0x128/0x180
kernel_init+0x2c/0x160
ret_from_fork+0x10/0x20
-> #0 (reservation_ww_class_acquire){+.+.}-{0:0}:
check_prev_add+0x114/0x790
validate_chain+0x594/0x6f0
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
drm_gem_lru_scan+0x1ac/0x440
msm_gem_shrinker_scan+0x17c/0x400 [msm]
do_shrink_slab+0x150/0x4a0
shrink_slab+0x144/0x460
shrink_one+0x9c/0x1b0
shrink_many+0x27c/0x5c0
shrink_node+0x344/0x550
balance_pgdat+0x2c0/0x988
kswapd+0x11c/0x318
kthread+0x10c/0x128
ret_from_fork+0x10/0x20
other info that might help us debug this:
Chain exists of:
reservation_ww_class_acquire --> reservation_ww_class_mutex --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(reservation_ww_class_mutex);
lock(fs_reclaim);
lock(reservation_ww_class_acquire);
*** DEADLOCK ***
1 lock held by kswapd0/82:
#0: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988
stack backtrace:
CPU: 4 UID: 0 PID: 82 Comm: kswapd0 Tainted: G W 7.0.0-debug+ #43 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: LENOVO 21BX0016US/21BX0016US, BIOS N3HET94W (1.66 ) 09/15/2025
Call trace:
show_stack+0x20/0x40 (C)
dump_stack_lvl+0x9c/0xd0
dump_stack+0x18/0x30
print_circular_bug+0x114/0x120
check_noncircular+0x178/0x198
check_prev_add+0x114/0x790
validate_chain+0x594/0x6f0
__lock_acquire+0x4d0/0xad0
lock_acquire.part.0+0xc4/0x248
lock_acquire+0x8c/0x248
drm_gem_lru_scan+0x1ac/0x440
msm_gem_shrinker_scan+0x17c/0x400 [msm]
do_shrink_slab+0x150/0x4a0
shrink_slab+0x144/0x460
shrink_one+0x9c/0x1b0
shrink_many+0x27c/0x5c0
shrink_node+0x344/0x550
balance_pgdat+0x2c0/0x988
kswapd+0x11c/0x318
kthread+0x10c/0x128
ret_from_fork+0x10/0x20
kswapd0 holding fs_reclaim calls the MSM shrinker, which calls
dma_resv_lock. This in turn acquires fs_reclaim.
Fix this deadlock by using dma_resv_trylock() instead, dropping the
subsequently unused passed wait-wound lock 'ticket'.
Patchwork: https://patchwork.freedesktop.org/patch/723564/
[rob: fixup compile errors, replace lockdep splat with somethin
---truncated---
Published:
2026-07-19
Score:
n/a
EPSS:
< 1% Very Low
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||
| Linux | Linux | affected |
|
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Remediation
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Advisories
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References
History
Sun, 19 Jul 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix shrinker deadlock With PROVE_LOCKING on an Snapdragon X1 and VM reclaim pressure, we see: ====================================================== WARNING: possible circular locking dependency detected 7.0.0-debug+ #43 Tainted: G W ------------------------------------------------------ kswapd0/82 is trying to acquire lock: ffff800080ec3870 (reservation_ww_class_acquire){+.+.}-{0:0}, at: msm_gem_shrinker_scan+0x17c/0x400 [msm] but task is already holding lock: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}-{0:0}: __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 fs_reclaim_acquire+0xd0/0xf0 dma_resv_lockdep+0x224/0x348 do_one_initcall+0x84/0x5d0 do_initcalls+0x194/0x1d8 kernel_init_freeable+0x128/0x180 kernel_init+0x2c/0x160 ret_from_fork+0x10/0x20 -> #1 (reservation_ww_class_mutex){+.+.}-{4:4}: __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 dma_resv_lockdep+0x1a8/0x348 do_one_initcall+0x84/0x5d0 do_initcalls+0x194/0x1d8 kernel_init_freeable+0x128/0x180 kernel_init+0x2c/0x160 ret_from_fork+0x10/0x20 -> #0 (reservation_ww_class_acquire){+.+.}-{0:0}: check_prev_add+0x114/0x790 validate_chain+0x594/0x6f0 __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 drm_gem_lru_scan+0x1ac/0x440 msm_gem_shrinker_scan+0x17c/0x400 [msm] do_shrink_slab+0x150/0x4a0 shrink_slab+0x144/0x460 shrink_one+0x9c/0x1b0 shrink_many+0x27c/0x5c0 shrink_node+0x344/0x550 balance_pgdat+0x2c0/0x988 kswapd+0x11c/0x318 kthread+0x10c/0x128 ret_from_fork+0x10/0x20 other info that might help us debug this: Chain exists of: reservation_ww_class_acquire --> reservation_ww_class_mutex --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(reservation_ww_class_mutex); lock(fs_reclaim); lock(reservation_ww_class_acquire); *** DEADLOCK *** 1 lock held by kswapd0/82: #0: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988 stack backtrace: CPU: 4 UID: 0 PID: 82 Comm: kswapd0 Tainted: G W 7.0.0-debug+ #43 PREEMPT(full) Tainted: [W]=WARN Hardware name: LENOVO 21BX0016US/21BX0016US, BIOS N3HET94W (1.66 ) 09/15/2025 Call trace: show_stack+0x20/0x40 (C) dump_stack_lvl+0x9c/0xd0 dump_stack+0x18/0x30 print_circular_bug+0x114/0x120 check_noncircular+0x178/0x198 check_prev_add+0x114/0x790 validate_chain+0x594/0x6f0 __lock_acquire+0x4d0/0xad0 lock_acquire.part.0+0xc4/0x248 lock_acquire+0x8c/0x248 drm_gem_lru_scan+0x1ac/0x440 msm_gem_shrinker_scan+0x17c/0x400 [msm] do_shrink_slab+0x150/0x4a0 shrink_slab+0x144/0x460 shrink_one+0x9c/0x1b0 shrink_many+0x27c/0x5c0 shrink_node+0x344/0x550 balance_pgdat+0x2c0/0x988 kswapd+0x11c/0x318 kthread+0x10c/0x128 ret_from_fork+0x10/0x20 kswapd0 holding fs_reclaim calls the MSM shrinker, which calls dma_resv_lock. This in turn acquires fs_reclaim. Fix this deadlock by using dma_resv_trylock() instead, dropping the subsequently unused passed wait-wound lock 'ticket'. Patchwork: https://patchwork.freedesktop.org/patch/723564/ [rob: fixup compile errors, replace lockdep splat with somethin ---truncated--- | |
| Title | drm/msm: Fix shrinker deadlock | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-19T15:40:05.530Z
Reserved: 2026-07-19T07:54:57.033Z
Link: CVE-2026-64100
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.