{"schema":"threatline.record/2","record":{"id":"CVE-2026-97416","aliases":[],"summary":"btrfs: balance: fix potential bg lookup failure in btrfs_may_alloc_data_chunk()","details":"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.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"Linux","vendor":"Linux","versions":[{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"9f37a6d6ae9e998232e2ba091ab4999cdf967e1b","status":"affected","versionType":"git"},{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2","status":"affected","versionType":"git"},{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"322f891b4d4fe64acb3351a0ffa62a7fa5ba7256","status":"affected","versionType":"git"},{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"81a664ed8b1a44c76b204c4bd0d751317a02c5cd","status":"affected","versionType":"git"},{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"9740dd0c17a4be8cc47a06c5ca5293471a7e286e","status":"affected","versionType":"git"},{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"59f75e0c8724d4adebc08c7dd3ff2358b80c21f7","status":"affected","versionType":"git"},{"version":"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7","lessThan":"18d32b0013efba19f7ad3e5b08d7aee813d604a6","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"Linux","vendor":"Linux","versions":[{"version":"4.16","status":"affected"},{"version":"0","lessThan":"4.16","status":"unaffected","versionType":"semver"},{"version":"5.10.271","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.222","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.189","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.158","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.53","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"Linux","ecosystem":null},"version":"9f37a6d6ae9e998232e2ba091ab4999cdf967e1b","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"Linux","ecosystem":null},"version":"322f891b4d4fe64acb3351a0ffa62a7fa5ba7256","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"Linux","ecosystem":null},"version":"81a664ed8b1a44c76b204c4bd0d751317a02c5cd","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"Linux","ecosystem":null},"version":"9740dd0c17a4be8cc47a06c5ca5293471a7e286e","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"Linux","ecosystem":null},"version":"59f75e0c8724d4adebc08c7dd3ff2358b80c21f7","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","source_modified_at":"2026-10-03T10:58:07.862Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"Linux","ecosystem":null},"version":"18d32b0013efba19f7ad3e5b08d7aee813d604a6","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00173,"percentile":0.06341,"score_date":"2026-10-23"},"published_at":"2026-09-24T16:03:23.731Z","modified_at":"2026-10-03T10:58:07.862Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-97416","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-10-03T10:58:07.862Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-97416","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/9f37a6d6ae9e998232e2ba091ab4999cdf967e1b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/322f891b4d4fe64acb3351a0ffa62a7fa5ba7256"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/81a664ed8b1a44c76b204c4bd0d751317a02c5cd"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-03T10:58:07.862Z","content_hash":"fbd3e1bd3a71b5ce1482ab03795cbf62e45c547837c320772a3107c7f78e9533"}}