CVE-2026-97416
In the Linux kernel, the following vulnerability has been resolved:
btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()
[BUG] Running btrfs balance can trigger a null-ptr-deref before relocating a data chunk when metadata corruption leaves a chunk in the chunk tree without a corresponding block group in the in-memory cache:
[CAUSE] __btrfs_balance() iterates the on-disk chunk tree and passes the chunk logical bytenr to btrfs_may_alloc_data_chunk() before relocating a data chunk. That helper then queries the in-memory block group cache:
A corrupt image can contain a chunk item whose matching block group item is missing, so no block group is ever inserted into the cache. In that case btrfs_lookup_block_group() returns NULL.
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The code only guards this with ASSERT(cache), which becomes a no-op when CONFIG_BTRFS_ASSERT is disabled. The subsequent dereference of cache->flags therefore crashes the kernel.
[FIX] Add a NULL check after btrfs_lookup_block_group() in btrfs_may_alloc_data_chunk() and print and error message for clarity.
Detalles técnicos trazas, registros y código del informe original
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
RIP: 0010:btrfs_may_alloc_data_chunk+0x40/0x1c0 fs/btrfs/volumes.c:3601
Call Trace:
__btrfs_balance fs/btrfs/volumes.c:4217 [inline]
btrfs_balance+0x2516/0x42b0 fs/btrfs/volumes.c:4604
btrfs_ioctl_balance fs/btrfs/ioctl.c:3577 [inline]
btrfs_ioctl+0x25cf/0x5b90 fs/btrfs/ioctl.c:5313
...
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_type = cache->flags; /* cache may be NULL */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: 0.17%
- Percentil entre todas las CVEs puntuadas: 6
- 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
- https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6
- https://git.kernel.org/stable/c/322f891b4d4fe64acb3351a0ffa62a7fa5ba7256
- https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7
- https://git.kernel.org/stable/c/81a664ed8b1a44c76b204c4bd0d751317a02c5cd
- https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e
- https://git.kernel.org/stable/c/9f37a6d6ae9e998232e2ba091ab4999cdf967e1b
- https://git.kernel.org/stable/c/e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-97416",
"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": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "9f37a6d6ae9e998232e2ba091ab4999cdf967e1b",
"versionType": "git"
},
{
"status": "affected",
"version": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2",
"versionType": "git"
},
{
"status": "affected",
"version": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "322f891b4d4fe64acb3351a0ffa62a7fa5ba7256",
"versionType": "git"
},
{
"status": "affected",
"version": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "81a664ed8b1a44c76b204c4bd0d751317a02c5cd",
"versionType": "git"
},
{
"status": "affected",
"version": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "9740dd0c17a4be8cc47a06c5ca5293471a7e286e",
"versionType": "git"
},
{
"status": "affected",
"version": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "59f75e0c8724d4adebc08c7dd3ff2358b80c21f7",
"versionType": "git"
},
{
"status": "affected",
"version": "a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7",
"lessThan": "18d32b0013efba19f7ad3e5b08d7aee813d604a6",
"versionType": "git"
}
],
"programFiles": [
"fs/btrfs/volumes.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/btrfs/volumes.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-24T17:17:19.340",
"references": [
{
"url": "https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/322f891b4d4fe64acb3351a0ffa62a7fa5ba7256",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/81a664ed8b1a44c76b204c4bd0d751317a02c5cd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/9f37a6d6ae9e998232e2ba091ab4999cdf967e1b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()\n\n[BUG]\nRunning btrfs balance can trigger a null-ptr-deref before relocating a\ndata chunk when metadata corruption leaves a chunk in the chunk tree\nwithout a corresponding block group in the in-memory cache:\n\n KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]\n RIP: 0010:btrfs_may_alloc_data_chunk+0x40/0x1c0 fs/btrfs/volumes.c:3601\n Call Trace:\n __btrfs_balance fs/btrfs/volumes.c:4217 [inline]\n btrfs_balance+0x2516/0x42b0 fs/btrfs/volumes.c:4604\n btrfs_ioctl_balance fs/btrfs/ioctl.c:3577 [inline]\n btrfs_ioctl+0x25cf/0x5b90 fs/btrfs/ioctl.c:5313\n ...\n\n[CAUSE]\n__btrfs_balance() iterates the on-disk chunk tree and passes the chunk\nlogical bytenr to btrfs_may_alloc_data_chunk() before relocating a data\nchunk. That helper then queries the in-memory block group cache:\n\n cache = btrfs_lookup_block_group(fs_info, chunk_offset);\n chunk_type = cache->flags; /* cache may be NULL */\n\nA corrupt image can contain a chunk item whose matching block group\nitem is missing, so no block group is ever inserted into the cache. In\nthat case btrfs_lookup_block_group() returns NULL.\n\nThe code only guards this with ASSERT(cache), which becomes a no-op when\nCONFIG_BTRFS_ASSERT is disabled. The subsequent dereference of\ncache->flags therefore crashes the kernel.\n\n[FIX]\nAdd a NULL check after btrfs_lookup_block_group() in\nbtrfs_may_alloc_data_chunk() and print and error message for clarity."
}
],
"lastModified": "2026-10-03T11:17:53.617",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}