{"id":"CVE-2026-97416","revision":"7e9c426d91c2449c8578411c3195f0b1","records":[{"revision":"7e9c426d91c2449c8578411c3195f0b1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-97416","aliases":[],"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":0,"publishedAt":"2026-09-24T16:03:23.731+00:00","modifiedAt":"2026-10-03T10:58:07.862+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/btrfs/volumes.c\"\n ],\n \"versions\": [\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"9f37a6d6ae9e998232e2ba091ab4999cdf967e1b\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"322f891b4d4fe64acb3351a0ffa62a7fa5ba7256\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"81a664ed8b1a44c76b204c4bd0d751317a02c5cd\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"9740dd0c17a4be8cc47a06c5ca5293471a7e286e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"59f75e0c8724d4adebc08c7dd3ff2358b80c21f7\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"a6f93c71d412ba8ed743152c3a54ad0b78dcd9c7\",\n \"lessThan\": \"18d32b0013efba19f7ad3e5b08d7aee813d604a6\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/btrfs/volumes.c\"\n ],\n \"versions\": [\n {\n \"version\": \"4.16\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"4.16\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.271\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.222\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.189\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.158\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.111\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.53\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/9f37a6d6ae9e998232e2ba091ab4999cdf967e1b","https://git.kernel.org/stable/c/e479236a8f4d85c4fb6b3f7c2556c21f583e2bf2","https://git.kernel.org/stable/c/322f891b4d4fe64acb3351a0ffa62a7fa5ba7256","https://git.kernel.org/stable/c/81a664ed8b1a44c76b204c4bd0d751317a02c5cd","https://git.kernel.org/stable/c/9740dd0c17a4be8cc47a06c5ca5293471a7e286e","https://git.kernel.org/stable/c/59f75e0c8724d4adebc08c7dd3ff2358b80c21f7","https://git.kernel.org/stable/c/18d32b0013efba19f7ad3e5b08d7aee813d604a6"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-97416","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-97416","identifiers":["CVE-2026-97416"]},"retained":false,"historicalAffected":[]}],"coverage":[]}