CVE-2024-49870
Estado: ModificadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix dentry leak in cachefiles_open_file()
A dentry leak may be caused when a lookup cookie and a cull are concurrent:
After that the following WARNING will be triggered when the backend folder is umounted:
Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released.
Therefore release that reference count in cachefiles_look_up_object() to fix the above issue and simplify the code.
Detalles técnicos trazas, registros y código del informe original
P1 | P2
-----------------------------------------------------------
cachefiles_lookup_cookie
cachefiles_look_up_object
lookup_one_positive_unlocked
// get dentry
cachefiles_cull
inode->i_flags |= S_KERNEL_FILE;
cachefiles_open_file
cachefiles_mark_inode_in_use
__cachefiles_mark_inode_in_use
can_use = false
if (!(inode->i_flags & S_KERNEL_FILE))
can_use = true
return false
return false
// Returns an error but doesn't put dentry
==================================================================
BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda]
WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70
CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25
RIP: 0010:umount_check+0x5d/0x70
Call Trace:
<TASK>
d_walk+0xda/0x2b0
do_one_tree+0x20/0x40
shrink_dcache_for_umount+0x2c/0x90
generic_shutdown_super+0x20/0x160
kill_block_super+0x1a/0x40
ext4_kill_sb+0x22/0x40
deactivate_locked_super+0x35/0x80
cleanup_mnt+0x104/0x160
==================================================================CVSS
- 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: 0.24%
- Percentil entre todas las CVEs puntuadas: 13
- Fecha de la puntuación: 5/10/2026
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-401
Referencias
- https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b
- https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151
- https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410
- https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c
- https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
JSON original (NVD)
Mostrar
{
"id": "CVE-2024-49870",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2024-49870",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2024-10-22T13:47:04.248927Z"
}
}
],
"cvssMetricV31": [
{
"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
}
]
},
"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": "1f08c925e7a38002bde509e66f6f891468848511",
"lessThan": "d32ff64c872d7e08e893c32ba6a2374583444410",
"versionType": "git"
},
{
"status": "affected",
"version": "1f08c925e7a38002bde509e66f6f891468848511",
"lessThan": "c7d10fa7d7691558ff967668494672415f5fa151",
"versionType": "git"
},
{
"status": "affected",
"version": "1f08c925e7a38002bde509e66f6f891468848511",
"lessThan": "e4a28489b310339b2b8187bec0a437709be551c1",
"versionType": "git"
},
{
"status": "affected",
"version": "1f08c925e7a38002bde509e66f6f891468848511",
"lessThan": "7fa2382f97421978514a419c93054eca69f5247b",
"versionType": "git"
},
{
"status": "affected",
"version": "1f08c925e7a38002bde509e66f6f891468848511",
"lessThan": "da6ef2dffe6056aad3435e6cf7c6471c2a62187c",
"versionType": "git"
}
],
"programFiles": [
"fs/cachefiles/namei.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.17",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.113",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.55",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.10.14",
"versionType": "semver",
"lessThanOrEqual": "6.10.*"
},
{
"status": "unaffected",
"version": "6.11.3",
"versionType": "semver",
"lessThanOrEqual": "6.11.*"
},
{
"status": "unaffected",
"version": "6.12",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/cachefiles/namei.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2024-10-21T18:15:08.413",
"references": [
{
"url": "https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-401"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: fix dentry leak in cachefiles_open_file()\n\nA dentry leak may be caused when a lookup cookie and a cull are concurrent:\n\n P1 | P2\n-----------------------------------------------------------\ncachefiles_lookup_cookie\n cachefiles_look_up_object\n lookup_one_positive_unlocked\n // get dentry\n cachefiles_cull\n inode->i_flags |= S_KERNEL_FILE;\n cachefiles_open_file\n cachefiles_mark_inode_in_use\n __cachefiles_mark_inode_in_use\n can_use = false\n if (!(inode->i_flags & S_KERNEL_FILE))\n can_use = true\n\t return false\n return false\n // Returns an error but doesn't put dentry\n\nAfter that the following WARNING will be triggered when the backend folder\nis umounted:\n\n==================================================================\nBUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda]\nWARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70\nCPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25\nRIP: 0010:umount_check+0x5d/0x70\nCall Trace:\n <TASK>\n d_walk+0xda/0x2b0\n do_one_tree+0x20/0x40\n shrink_dcache_for_umount+0x2c/0x90\n generic_shutdown_super+0x20/0x160\n kill_block_super+0x1a/0x40\n ext4_kill_sb+0x22/0x40\n deactivate_locked_super+0x35/0x80\n cleanup_mnt+0x104/0x160\n==================================================================\n\nWhether cachefiles_open_file() returns true or false, the reference count\nobtained by lookup_positive_unlocked() in cachefiles_look_up_object()\nshould be released.\n\nTherefore release that reference count in cachefiles_look_up_object() to\nfix the above issue and simplify the code."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: cachefiles: se corrige la pérdida de dentry en cachefiles_open_file(). Una pérdida de dentry puede producirse cuando una cookie de búsqueda y un cull son concurrentes: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // obtener dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Devuelve un error pero no coloca dentry Después de eso, se activará la siguiente ADVERTENCIA cuando se desmonte la carpeta del backend: ===================================================================== ERROR: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} todavía en uso (1) [desmontaje de ext4 sda] ADVERTENCIA: CPU: 4 PID: 359261 en fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount No contaminado 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Rastreo de llamadas: d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ==================================================================== Independientemente de si cachefiles_open_file() devuelve verdadero o falso, el recuento de referencias obtenido por lookup_positive_unlocked() en cachefiles_look_up_object() debe liberarse. Por lo tanto, libere ese recuento de referencias en cachefiles_look_up_object() para solucionar el problema anterior y simplificar el código."
}
],
"lastModified": "2026-06-17T08:00:37.487",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "09358D68-A717-469E-B900-8002A642E29A",
"versionEndExcluding": "6.1.113",
"versionStartIncluding": "5.17"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E90B9576-56C4-47BC-AAB0-C5B2D438F5D0",
"versionEndExcluding": "6.6.55",
"versionStartIncluding": "6.2"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4C16BCE0-FFA0-4599-BE0A-1FD65101C021",
"versionEndExcluding": "6.10.14",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "54D9C704-D679-41A7-9C40-10A6B1E7FFE9",
"versionEndExcluding": "6.11.3",
"versionStartIncluding": "6.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7F361E1D-580F-4A2D-A509-7615F73167A1"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}