CVE-2026-64100
Estado: AnalizadaMedia (5.5)—
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:
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---
Detalles técnicos trazas, registros y código del informe original
======================================================
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+0x10/0x20CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.12%
- Percentil entre todas las CVEs puntuadas: 2
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-667
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64100",
"cveTags": [],
"metrics": {
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{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1.8
}
]
},
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{
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],
"programFiles": [
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"defaultStatus": "affected"
}
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}
],
"published": "2026-07-19T16:17:51.140",
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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"tags": [
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],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
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"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-667"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/msm: Fix shrinker deadlock\n\nWith PROVE_LOCKING on an Snapdragon X1 and VM reclaim pressure, we see:\n\n ======================================================\n WARNING: possible circular locking dependency detected\n 7.0.0-debug+ #43 Tainted: G W\n ------------------------------------------------------\n kswapd0/82 is trying to acquire lock:\n ffff800080ec3870 (reservation_ww_class_acquire){+.+.}-{0:0}, at: msm_gem_shrinker_scan+0x17c/0x400 [msm]\n\n but task is already holding lock:\n ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988\n\n which lock already depends on the new lock.\n\n the existing dependency chain (in reverse order) is:\n\n -> #2 (fs_reclaim){+.+.}-{0:0}:\n __lock_acquire+0x4d0/0xad0\n lock_acquire.part.0+0xc4/0x248\n lock_acquire+0x8c/0x248\n fs_reclaim_acquire+0xd0/0xf0\n dma_resv_lockdep+0x224/0x348\n do_one_initcall+0x84/0x5d0\n do_initcalls+0x194/0x1d8\n kernel_init_freeable+0x128/0x180\n kernel_init+0x2c/0x160\n ret_from_fork+0x10/0x20\n\n -> #1 (reservation_ww_class_mutex){+.+.}-{4:4}:\n __lock_acquire+0x4d0/0xad0\n lock_acquire.part.0+0xc4/0x248\n lock_acquire+0x8c/0x248\n dma_resv_lockdep+0x1a8/0x348\n do_one_initcall+0x84/0x5d0\n do_initcalls+0x194/0x1d8\n kernel_init_freeable+0x128/0x180\n kernel_init+0x2c/0x160\n ret_from_fork+0x10/0x20\n\n -> #0 (reservation_ww_class_acquire){+.+.}-{0:0}:\n check_prev_add+0x114/0x790\n validate_chain+0x594/0x6f0\n __lock_acquire+0x4d0/0xad0\n lock_acquire.part.0+0xc4/0x248\n lock_acquire+0x8c/0x248\n drm_gem_lru_scan+0x1ac/0x440\n msm_gem_shrinker_scan+0x17c/0x400 [msm]\n do_shrink_slab+0x150/0x4a0\n shrink_slab+0x144/0x460\n shrink_one+0x9c/0x1b0\n shrink_many+0x27c/0x5c0\n shrink_node+0x344/0x550\n balance_pgdat+0x2c0/0x988\n kswapd+0x11c/0x318\n kthread+0x10c/0x128\n ret_from_fork+0x10/0x20\n\n other info that might help us debug this:\n Chain exists of:\n reservation_ww_class_acquire --> reservation_ww_class_mutex --> fs_reclaim\n Possible unsafe locking scenario:\n CPU0 CPU1\n ---- ----\n lock(fs_reclaim);\n lock(reservation_ww_class_mutex);\n lock(fs_reclaim);\n lock(reservation_ww_class_acquire);\n\n *** DEADLOCK ***\n 1 lock held by kswapd0/82:\n #0: ffffc31709b263b8 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x88/0x988\n\n stack backtrace:\n CPU: 4 UID: 0 PID: 82 Comm: kswapd0 Tainted: G W 7.0.0-debug+ #43 PREEMPT(full)\n Tainted: [W]=WARN\n Hardware name: LENOVO 21BX0016US/21BX0016US, BIOS N3HET94W (1.66 ) 09/15/2025\n Call trace:\n show_stack+0x20/0x40 (C)\n dump_stack_lvl+0x9c/0xd0\n dump_stack+0x18/0x30\n print_circular_bug+0x114/0x120\n check_noncircular+0x178/0x198\n check_prev_add+0x114/0x790\n validate_chain+0x594/0x6f0\n __lock_acquire+0x4d0/0xad0\n lock_acquire.part.0+0xc4/0x248\n lock_acquire+0x8c/0x248\n drm_gem_lru_scan+0x1ac/0x440\n msm_gem_shrinker_scan+0x17c/0x400 [msm]\n do_shrink_slab+0x150/0x4a0\n shrink_slab+0x144/0x460\n shrink_one+0x9c/0x1b0\n shrink_many+0x27c/0x5c0\n shrink_node+0x344/0x550\n balance_pgdat+0x2c0/0x988\n kswapd+0x11c/0x318\n kthread+0x10c/0x128\n ret_from_fork+0x10/0x20\n\nkswapd0 holding fs_reclaim calls the MSM shrinker, which calls\ndma_resv_lock. This in turn acquires fs_reclaim.\n\nFix this deadlock by using dma_resv_trylock() instead, dropping the\nsubsequently unused passed wait-wound lock 'ticket'.\n\nPatchwork: https://patchwork.freedesktop.org/patch/723564/\n[rob: fixup compile errors, replace lockdep splat with somethin\n---truncated---"
}
],
"lastModified": "2026-08-11T16:04:37.380",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
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