CVE-2024-49881
Estado: ModificadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
ext4: update orig_path in ext4_find_extent()
In ext4_find_extent(), if the path is not big enough, we free it and set *orig_path to NULL. But after reallocating and successfully initializing the path, we don't update *orig_path, in which case the caller gets a valid path but a NULL ppath, and this may cause a NULL pointer dereference or a path memory leak. For example:
Therefore, *orig_path is updated when the extent lookup succeeds, so that the caller can safely use path or *ppath.
Detalles técnicos trazas, registros y código del informe original
ext4_split_extent
path = *ppath = 2000
ext4_find_extent
if (depth > path[0].p_maxdepth)
kfree(path = 2000);
*orig_path = path = NULL;
path = kcalloc() = 3000
ext4_split_extent_at(*ppath = NULL)
path = *ppath;
ex = path[depth].p_ext;
// NULL pointer dereference!
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000010
CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847
RIP: 0010:ext4_split_extent_at+0x6d/0x560
Call Trace:
<TASK>
ext4_split_extent.isra.0+0xcb/0x1b0
ext4_ext_convert_to_initialized+0x168/0x6c0
ext4_ext_handle_unwritten_extents+0x325/0x4d0
ext4_ext_map_blocks+0x520/0xdb0
ext4_map_blocks+0x2b0/0x690
ext4_iomap_begin+0x20e/0x2c0
[...]
==================================================================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: 0.25%
- Percentil entre todas las CVEs puntuadas: 15
- 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-476
Referencias
- https://git.kernel.org/stable/c/11b230100d6801c014fab2afabc8bdea304c1b96
- https://git.kernel.org/stable/c/5b4b2dcace35f618fe361a87bae6f0d13af31bc1
- https://git.kernel.org/stable/c/6766937d0327000ac1b87c97bbecdd28b0dd6599
- https://git.kernel.org/stable/c/6801ed1298204d16a38571091e31178bfdc3c679
- https://git.kernel.org/stable/c/a9fcb1717d75061d3653ed69365c8d45331815cd
- https://git.kernel.org/stable/c/b63481b3a388ee2df9e295f97273226140422a42
- https://git.kernel.org/stable/c/ec0c0beb9b777cdd1edd7df9b36e0f3e67e2bdff
- https://git.kernel.org/stable/c/f55ecc58d07a6c1f6d6d5b5af125c25f8da0bda2
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
JSON original (NVD)
Mostrar
{
"id": "CVE-2024-49881",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2024-49881",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2024-10-22T13:45:38.096654Z"
}
}
],
"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": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "ec0c0beb9b777cdd1edd7df9b36e0f3e67e2bdff",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "6766937d0327000ac1b87c97bbecdd28b0dd6599",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "a9fcb1717d75061d3653ed69365c8d45331815cd",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "6801ed1298204d16a38571091e31178bfdc3c679",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "f55ecc58d07a6c1f6d6d5b5af125c25f8da0bda2",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "b63481b3a388ee2df9e295f97273226140422a42",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "11b230100d6801c014fab2afabc8bdea304c1b96",
"versionType": "git"
},
{
"status": "affected",
"version": "10809df84a4d868db61af621bae3658494165279",
"lessThan": "5b4b2dcace35f618fe361a87bae6f0d13af31bc1",
"versionType": "git"
}
],
"programFiles": [
"fs/ext4/extents.c",
"fs/ext4/move_extent.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.19.323",
"versionType": "semver",
"lessThanOrEqual": "4.19.*"
},
{
"status": "unaffected",
"version": "5.10.227",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.168",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"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/ext4/extents.c",
"fs/ext4/move_extent.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2024-10-21T18:15:10.560",
"references": [
{
"url": "https://git.kernel.org/stable/c/11b230100d6801c014fab2afabc8bdea304c1b96",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5b4b2dcace35f618fe361a87bae6f0d13af31bc1",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6766937d0327000ac1b87c97bbecdd28b0dd6599",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6801ed1298204d16a38571091e31178bfdc3c679",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a9fcb1717d75061d3653ed69365c8d45331815cd",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b63481b3a388ee2df9e295f97273226140422a42",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ec0c0beb9b777cdd1edd7df9b36e0f3e67e2bdff",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f55ecc58d07a6c1f6d6d5b5af125c25f8da0bda2",
"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"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: update orig_path in ext4_find_extent()\n\nIn ext4_find_extent(), if the path is not big enough, we free it and set\n*orig_path to NULL. But after reallocating and successfully initializing\nthe path, we don't update *orig_path, in which case the caller gets a\nvalid path but a NULL ppath, and this may cause a NULL pointer dereference\nor a path memory leak. For example:\n\next4_split_extent\n path = *ppath = 2000\n ext4_find_extent\n if (depth > path[0].p_maxdepth)\n kfree(path = 2000);\n *orig_path = path = NULL;\n path = kcalloc() = 3000\n ext4_split_extent_at(*ppath = NULL)\n path = *ppath;\n ex = path[depth].p_ext;\n // NULL pointer dereference!\n\n==================================================================\nBUG: kernel NULL pointer dereference, address: 0000000000000010\nCPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847\nRIP: 0010:ext4_split_extent_at+0x6d/0x560\nCall Trace:\n <TASK>\n ext4_split_extent.isra.0+0xcb/0x1b0\n ext4_ext_convert_to_initialized+0x168/0x6c0\n ext4_ext_handle_unwritten_extents+0x325/0x4d0\n ext4_ext_map_blocks+0x520/0xdb0\n ext4_map_blocks+0x2b0/0x690\n ext4_iomap_begin+0x20e/0x2c0\n[...]\n==================================================================\n\nTherefore, *orig_path is updated when the extent lookup succeeds, so that\nthe caller can safely use path or *ppath."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: actualización de orig_path en ext4_find_extent() En ext4_find_extent(), si la ruta no es lo suficientemente grande, la liberamos y establecemos *orig_path en NULL. Pero después de reasignar e inicializar correctamente la ruta, no actualizamos *orig_path, en cuyo caso el llamador obtiene una ruta válida pero un ppath NULL, y esto puede causar una desreferencia de puntero NULL o una pérdida de memoria de ruta. Por ejemplo: ext4_split_extent path = *ppath = 2000 ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path = 2000); *orig_path = path = NULL; path = kcalloc() = 3000 ext4_split_extent_at(*ppath = NULL) path = *ppath; ex = path[depth].p_ext; // ¡Desreferencia de puntero NULL! ===================================================================== ERROR: Desreferencia de puntero NULL del núcleo, dirección: 000000000000010 CPU: 6 UID: 0 PID: 576 Comm: fsstress No contaminado 6.11.0-rc2-dirty #847 RIP: 0010:ext4_split_extent_at+0x6d/0x560 Rastreo de llamada: ext4_split_extent.isra.0+0xcb/0x1b0 ext4_ext_convert_to_initialized+0x168/0x6c0 ext4_ext_handle_unwritten_extents+0x325/0x4d0 ext4_ext_map_blocks+0x520/0xdb0 ext4_map_blocks+0x2b0/0x690 ext4_iomap_begin+0x20e/0x2c0 [...] ====================================================================== Por lo tanto, *orig_path se actualiza cuando la búsqueda de extensión tiene éxito, de modo que el llamador puede usar path o *ppath de forma segura."
}
],
"lastModified": "2026-06-17T08:00:38.927",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5C882E98-F19D-47B6-A807-73BB9ABA763C",
"versionEndExcluding": "5.10.227",
"versionStartIncluding": "3.18"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4D51C05D-455B-4D8D-89E7-A58E140B864C",
"versionEndExcluding": "5.15.168",
"versionStartIncluding": "5.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D01BD22E-ACD1-4618-9D01-6116570BE1EE",
"versionEndExcluding": "6.1.113",
"versionStartIncluding": "5.16"
},
{
"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"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}