btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()
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 pr
CVE-2026-97416
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-97416
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"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"
}
]- Related CVEs
- CVE-2026-97416
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #8307 · Revision 1
- Added to Heist Feed
- Publisher date