{"id":"CVE-2024-41067","summary":"btrfs: scrub: handle RST lookup error correctly","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: scrub: handle RST lookup error correctly\n\n[BUG]\nWhen running btrfs/060 with forced RST feature, it would crash the\nfollowing ASSERT() inside scrub_read_endio():\n\n\tASSERT(sector_nr \u003c stripe-\u003enr_sectors);\n\nBefore that, we would have tree dump from\nbtrfs_get_raid_extent_offset(), as we failed to find the RST entry for\nthe range.\n\n[CAUSE]\nInside scrub_submit_extent_sector_read() every time we allocated a new\nbbio we immediately called btrfs_map_block() to make sure there was some\nRST range covering the scrub target.\n\nBut if btrfs_map_block() fails, we immediately call endio for the bbio,\nwhile the bbio is newly allocated, it's completely empty.\n\nThen inside scrub_read_endio(), we go through the bvecs to find\nthe sector number (as bi_sector is no longer reliable if the bio is\nsubmitted to lower layers).\n\nAnd since the bio is empty, such bvecs iteration would not find any\nsector matching the sector, and return sector_nr == stripe-\u003enr_sectors,\ntriggering the ASSERT().\n\n[FIX]\nInstead of calling btrfs_map_block() after allocating a new bbio, call\nbtrfs_map_block() first.\n\nSince our only objective of calling btrfs_map_block() is only to update\nstripe_len, there is really no need to do that after btrfs_alloc_bio().\n\nThis new timing would avoid the problem of handling empty bbio\ncompletely, and in fact fixes a possible race window for the old code,\nwhere if the submission thread is the only owner of the pending_io, the\nscrub would never finish (since we didn't decrease the pending_io\ncounter).\n\nAlthough the root cause of RST lookup failure still needs to be\naddressed.","modified":"2026-04-02T12:17:24.894016Z","published":"2024-07-29T14:57:28.543Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/41xxx/CVE-2024-41067.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/17d1fd302a53d7e456a7412da74be74a0cf63a72"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2c49908634a2b97b1c3abe0589be2739ac5e7fd5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/41xxx/CVE-2024-41067.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-41067"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9acaa64187f9b4cbb75622883c96ea1a893d5431"},{"fixed":"17d1fd302a53d7e456a7412da74be74a0cf63a72"},{"fixed":"2c49908634a2b97b1c3abe0589be2739ac5e7fd5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-41067.json"}}],"schema_version":"1.7.5"}