CVE-2026-97416 (GCVE-0-2026-97416)
Vulnerability from cvelistv5 – Published: 2026-09-24 16:03 – Updated: 2026-10-03 10:58
VLAI
EPSS
VEX
Title
btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()
Summary
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:
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
...
[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:
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_type = cache->flags; /* cache may be NULL */
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.
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.
Severity
No CVSS data available.
Assigner
References
7 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < 9f37a6d6ae9e998232e2ba091ab4999cdf967e1b
(git)
Affected: a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2 (git) Affected: a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < 322f891b4d4fe64acb3351a0ffa62a7fa5ba7256 (git) Affected: a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < 81a664ed8b1a44c76b204c4bd0d751317a02c5cd (git) Affected: a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < 9740dd0c17a4be8cc47a06c5ca5293471a7e286e (git) Affected: a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < 59f75e0c8724d4adebc08c7dd3ff2358b80c21f7 (git) Affected: a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 , < 18d32b0013efba19f7ad3e5b08d7aee813d604a6 (git) |
guessed | |
| Linux | Linux |
Affected:
4.16
Unaffected: 0 , < 4.16 (semver) Unaffected: 5.10.271 , ≤ 5.10.* (semver) Unaffected: 5.15.222 , ≤ 5.15.* (semver) Unaffected: 6.1.189 , ≤ 6.1.* (semver) Unaffected: 6.6.158 , ≤ 6.6.* (semver) Unaffected: 6.12.111 , ≤ 6.12.* (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
{
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},
{
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"version": "6.1.189",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "6.6.158",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "6.18.53",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
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"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "4.16",
"vulnerable": true
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{
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},
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"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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{
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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-\u003eflags; /* 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-\u003eflags 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."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-03T10:58:07.862Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/9f37a6d6ae9e998232e2ba091ab4999cdf967e1b"
},
{
"url": "https://git.kernel.org/stable/c/e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2"
},
{
"url": "https://git.kernel.org/stable/c/322f891b4d4fe64acb3351a0ffa62a7fa5ba7256"
},
{
"url": "https://git.kernel.org/stable/c/81a664ed8b1a44c76b204c4bd0d751317a02c5cd"
},
{
"url": "https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e"
},
{
"url": "https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7"
},
{
"url": "https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6"
}
],
"title": "btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-97416",
"datePublished": "2026-09-24T16:03:23.731Z",
"dateReserved": "2026-09-24T14:53:16.867Z",
"dateUpdated": "2026-10-03T10:58:07.862Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
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"cve": "CVE-2026-97416",
"date": "2026-11-14",
"epss": "0.00173",
"percentile": "0.06762"
},
"microsoft_vex": {
"current_release_date": "2026-10-22T01:11:42.000Z",
"cve": "CVE-2026-97416",
"id": "msrc_CVE-2026-97416",
"initial_release_date": "2026-09-28T00:06:16.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "1",
"product_status:under_investigation": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-97416.json",
"version": "4"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
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"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/btrfs/volumes.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"versions": [
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},
{
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"status": "unaffected",
"version": "6.1.189",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
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"version": "6.6.158",
"versionType": "semver"
},
{
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"version": "6.12.111",
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"version": "6.18.53",
"versionType": "semver"
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{
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"versionType": "original_commit_for_fix"
}
]
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],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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-\u003eflags; /* 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-\u003eflags 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."
}
],
"id": "CVE-2026-97416",
"lastModified": "2026-10-03T11:17:53.617",
"metrics": {},
"published": "2026-09-24T17:17:19.340",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6"
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},
{
"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"
},
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"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"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-11-07T11:29:05+00:00",
"cve": "CVE-2026-97416",
"id": "CVE-2026-97416",
"initial_release_date": "2026-09-24T00:00:00+00:00",
"product_status:known_affected": "15",
"product_status:known_not_affected": "188",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97416.json",
"version": "3"
}
}
}
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| Author | Source | Type | Date | Other |
|---|
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.