{"api_version":"1","generated_at":"2026-10-02T17:33:31+00:00","cve":"CVE-2026-97416","urls":{"html":"https://cve.report/CVE-2026-97416","api":"https://cve.report/api/cve/CVE-2026-97416.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97416","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97416"},"summary":{"title":"btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-24 17:17:19","updated_at":"2026-09-25 13:17:25"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e","name":"https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6","name":"https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7","name":"https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97416","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 9740dd0c17a4be8cc47a06c5ca5293471a7e286e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 59f75e0c8724d4adebc08c7dd3ff2358b80c21f7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7 18d32b0013efba19f7ad3e5b08d7aee813d604a6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"97416","cve":"CVE-2026-97416","epss":"0.001660000","percentile":"0.052110000","score_date":"2026-09-27","updated_at":"2026-09-28 00:02:24"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/btrfs/volumes.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"9740dd0c17a4be8cc47a06c5ca5293471a7e286e","status":"affected","version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","versionType":"git"},{"lessThan":"59f75e0c8724d4adebc08c7dd3ff2358b80c21f7","status":"affected","version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","versionType":"git"},{"lessThan":"18d32b0013efba19f7ad3e5b08d7aee813d604a6","status":"affected","version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/btrfs/volumes.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.16"},{"lessThan":"4.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"4.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"4.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"4.16","vulnerable":true}],"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->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."}],"providerMetadata":{"dateUpdated":"2026-09-25T12:43:51.311Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"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":"2026-09-25T12:43:51.311Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-24 17:17:19","lastModifiedDate":"2026-09-25 13:17:25","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"97416","Ordinal":"1","Title":"btrfs: balance: fix potential bg lookup failure in btrfs_may_all","CVE":"CVE-2026-97416","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"97416","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"btrfs: balance: fix potential bg lookup failure in btrfs_may_all"}]}}}