CVE-2026-68150
Estado: RecibidaSin puntuar—
In the Linux kernel, the following vulnerability has been resolved:
fs/super: fix emergency thaw double-unlock of s_umount
do_thaw_all() iterates over all superblocks via __iterate_supers() with SUPER_ITER_EXCL, which acquires s_umount exclusively before calling the callback and releases it afterwards. However, the callback do_thaw_all_callback() calls thaw_super_locked() which unconditionally releases s_umount on every code path. This results in a second unlock attempt in __iterate_supers() that corrupts the rwsem state, triggering a DEBUG_RWSEMS warning:
Fix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount in the callback via super_lock_excl() before calling thaw_super_locked(). This matches the locking pattern expected by thaw_super_locked() and eliminates the double unlock.
Leer descripción completaMostrar menos
While at it, remove the dead 'return;' at the end of do_thaw_all_callback().
Detalles técnicos trazas, registros y código del informe original
[ 182.601148] sysrq: Emergency Thaw of all frozen filesystems [ 182.601865] ------------[ cut here ]------------ [ 182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty [ 182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53 [ 182.604578] Modules linked in: [ 182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy) [ 182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014 [ 182.606417] Workqueue: events do_thaw_all [ 182.606750] RIP: 0010:up_write+0xaf/0x170 [ 182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 <67> 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d [ 182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246 [ 182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870 [ 182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10 [ 182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80 [ 182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000 [ 182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800 [ 182.612009] FS: 0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000 [ 182.612670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0 [ 182.613722] Call Trace: [ 182.613946] <TASK> [ 182.614130] __iterate_supers+0x128/0x150 [ 182.614463] do_thaw_all+0x1b/0x30 [ 182.614759] process_scheduled_works+0xbb/0x3f0 [ 182.615150] ? __pfx_worker_thread+0x10/0x10 [ 182.615499] worker_thread+0x129/0x270 [ 182.615816] ? __pfx_worker_thread+0x10/0x10 [ 182.616201] kthread+0xe2/0x120 [ 182.616469] ? __pfx_kthread+0x10/0x10 [ 182.616792] ret_from_fork+0x15b/0x240 [ 182.617115] ? __pfx_kthread+0x10/0x10 [ 182.617426] ret_from_fork_asm+0x1a/0x30 [ 182.617761] </TASK> [ 182.617968] ---[ end trace 0000000000000000 ]--- [ 182.618412] Emergency Thaw complete
CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.21%
- Percentil entre todas las CVEs puntuadas: 10
- 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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-68150",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "96a7883817a29fcbb46f70f0302ed455f7203c74",
"lessThan": "79e04370657a2581e3189f9c7fc166e7c4fbab3a",
"versionType": "git"
},
{
"status": "affected",
"version": "2992476528aeecbaee17ba0a6396a817481205a3",
"lessThan": "c78e38745ff1b0457c4551e7f75ea15842df1169",
"versionType": "git"
},
{
"status": "affected",
"version": "2992476528aeecbaee17ba0a6396a817481205a3",
"lessThan": "64017df6e61a3ce7159cee284109b92009985361",
"versionType": "git"
},
{
"status": "affected",
"version": "2992476528aeecbaee17ba0a6396a817481205a3",
"lessThan": "503d67fbaec6fdeaba391cb497675071db9d16ea",
"versionType": "git"
}
],
"programFiles": [
"fs/super.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/super.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-08-10T13:20:01.010",
"references": [
{
"url": "https://git.kernel.org/stable/c/503d67fbaec6fdeaba391cb497675071db9d16ea",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/64017df6e61a3ce7159cee284109b92009985361",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/79e04370657a2581e3189f9c7fc166e7c4fbab3a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c78e38745ff1b0457c4551e7f75ea15842df1169",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/super: fix emergency thaw double-unlock of s_umount\n\ndo_thaw_all() iterates over all superblocks via __iterate_supers()\nwith SUPER_ITER_EXCL, which acquires s_umount exclusively before\ncalling the callback and releases it afterwards. However, the\ncallback do_thaw_all_callback() calls thaw_super_locked() which\nunconditionally releases s_umount on every code path. This results\nin a second unlock attempt in __iterate_supers() that corrupts the\nrwsem state, triggering a DEBUG_RWSEMS warning:\n\n[ 182.601148] sysrq: Emergency Thaw of all frozen filesystems\n[ 182.601865] ------------[ cut here ]------------\n[ 182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty\n[ 182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53\n[ 182.604578] Modules linked in:\n[ 182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy)\n[ 182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014\n[ 182.606417] Workqueue: events do_thaw_all\n[ 182.606750] RIP: 0010:up_write+0xaf/0x170\n[ 182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 <67> 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d\n[ 182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246\n[ 182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870\n[ 182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10\n[ 182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80\n[ 182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000\n[ 182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800\n[ 182.612009] FS: 0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000\n[ 182.612670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[ 182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0\n[ 182.613722] Call Trace:\n[ 182.613946] <TASK>\n[ 182.614130] __iterate_supers+0x128/0x150\n[ 182.614463] do_thaw_all+0x1b/0x30\n[ 182.614759] process_scheduled_works+0xbb/0x3f0\n[ 182.615150] ? __pfx_worker_thread+0x10/0x10\n[ 182.615499] worker_thread+0x129/0x270\n[ 182.615816] ? __pfx_worker_thread+0x10/0x10\n[ 182.616201] kthread+0xe2/0x120\n[ 182.616469] ? __pfx_kthread+0x10/0x10\n[ 182.616792] ret_from_fork+0x15b/0x240\n[ 182.617115] ? __pfx_kthread+0x10/0x10\n[ 182.617426] ret_from_fork_asm+0x1a/0x30\n[ 182.617761] </TASK>\n[ 182.617968] ---[ end trace 0000000000000000 ]---\n[ 182.618412] Emergency Thaw complete\n\nFix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount\nin the callback via super_lock_excl() before calling\nthaw_super_locked(). This matches the locking pattern expected by\nthaw_super_locked() and eliminates the double unlock.\n\nWhile at it, remove the dead 'return;' at the end of\ndo_thaw_all_callback()."
}
],
"lastModified": "2026-08-23T13:16:34.210",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}