{"id":"AZL-62696","summary":"CVE-2024-41067 affecting package kernel 6.6.126.1-1","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":"2026-04-01T05:20:07.719978Z","published":"2024-07-29T15:15:14Z","upstream":["CVE-2024-41067"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-41067"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.126.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-62696.json"}}],"schema_version":"1.7.5"}