CVE-2025-40119
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix potential null deref in ext4_mb_init()
In ext4_mb_init(), ext4_mb_avg_fragment_size_destroy() may be called when sbi->s_mb_avg_fragment_size remains uninitialized (e.g., if groupinfo slab cache allocation fails). Since ext4_mb_avg_fragment_size_destroy() lacks null pointer checking, this leads to a null pointer dereference.
Therefore, add necessary null check to ext4_mb_avg_fragment_size_destroy() to prevent this issue. The same fix is also applied to ext4_mb_largest_free_orders_destroy().
Detalles técnicos trazas, registros y código del informe original
================================================================== EXT4-fs: no memory for groupinfo slab cache BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: Oops: 0002 [#1] SMP PTI CPU:2 UID: 0 PID: 87 Comm:mount Not tainted 6.17.0-rc2 #1134 PREEMPT(none) RIP: 0010:_raw_spin_lock_irqsave+0x1b/0x40 Call Trace: <TASK> xa_destroy+0x61/0x130 ext4_mb_init+0x483/0x540 __ext4_fill_super+0x116d/0x17b0 ext4_fill_super+0xd3/0x280 get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x29/0xd0 do_new_mount+0x197/0x300 __x64_sys_mount+0x116/0x150 do_syscall_64+0x50/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ==================================================================
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: 0.20%
- Percentil entre todas las CVEs puntuadas: 9
- 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)
⚠ 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-2025-40119",
"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": "d99d714f714c9492dc64d8ab4329b083dbfa9cab",
"lessThan": "08d9175578d6a8e9b81921898fbf01aa669cd2be",
"versionType": "git"
},
{
"status": "affected",
"version": "f7eaacbb4e54f8a6c6674c16eff54f703ea63d5e",
"lessThan": "00110f3cfc9b34b2dfee2a6c9e55a0ae6df125ae",
"versionType": "git"
},
{
"status": "affected",
"version": "f7eaacbb4e54f8a6c6674c16eff54f703ea63d5e",
"lessThan": "3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188",
"versionType": "git"
}
],
"programFiles": [
"fs/ext4/mballoc.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.17",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.17.3",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/ext4/mballoc.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-11-12T11:15:41.237",
"references": [
{
"url": "https://git.kernel.org/stable/c/00110f3cfc9b34b2dfee2a6c9e55a0ae6df125ae",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/08d9175578d6a8e9b81921898fbf01aa669cd2be",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix potential null deref in ext4_mb_init()\n\nIn ext4_mb_init(), ext4_mb_avg_fragment_size_destroy() may be called\nwhen sbi->s_mb_avg_fragment_size remains uninitialized (e.g., if groupinfo\nslab cache allocation fails). Since ext4_mb_avg_fragment_size_destroy()\nlacks null pointer checking, this leads to a null pointer dereference.\n\n==================================================================\nEXT4-fs: no memory for groupinfo slab cache\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nPGD 0 P4D 0\nOops: Oops: 0002 [#1] SMP PTI\nCPU:2 UID: 0 PID: 87 Comm:mount Not tainted 6.17.0-rc2 #1134 PREEMPT(none)\nRIP: 0010:_raw_spin_lock_irqsave+0x1b/0x40\nCall Trace:\n <TASK>\n xa_destroy+0x61/0x130\n ext4_mb_init+0x483/0x540\n __ext4_fill_super+0x116d/0x17b0\n ext4_fill_super+0xd3/0x280\n get_tree_bdev_flags+0x132/0x1d0\n vfs_get_tree+0x29/0xd0\n do_new_mount+0x197/0x300\n __x64_sys_mount+0x116/0x150\n do_syscall_64+0x50/0x1c0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n==================================================================\n\nTherefore, add necessary null check to ext4_mb_avg_fragment_size_destroy()\nto prevent this issue. The same fix is also applied to\next4_mb_largest_free_orders_destroy()."
}
],
"lastModified": "2026-06-17T09:21:17.827",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}