{"id":"CVE-2024-44941","summary":"f2fs: fix to cover read extent cache access with lock","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to cover read extent cache access with lock\n\nsyzbot reports a f2fs bug as below:\n\nBUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46\nRead of size 4 at addr ffff8880739ab220 by task syz-executor200/5097\n\nCPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114\n print_address_description mm/kasan/report.c:377 [inline]\n print_report+0x169/0x550 mm/kasan/report.c:488\n kasan_report+0x143/0x180 mm/kasan/report.c:601\n sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46\n do_read_inode fs/f2fs/inode.c:509 [inline]\n f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560\n f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237\n generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413\n exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444\n exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584\n do_handle_to_path fs/fhandle.c:155 [inline]\n handle_to_path fs/fhandle.c:210 [inline]\n do_handle_open+0x495/0x650 fs/fhandle.c:226\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nWe missed to cover sanity_check_extent_cache() w/ extent cache lock,\nso, below race case may happen, result in use after free issue.\n\n- f2fs_iget\n - do_read_inode\n  - f2fs_init_read_extent_tree\n  : add largest extent entry in to cache\n\t\t\t\t\t- shrink\n\t\t\t\t\t - f2fs_shrink_read_extent_tree\n\t\t\t\t\t  - __shrink_extent_tree\n\t\t\t\t\t   - __detach_extent_node\n\t\t\t\t\t   : drop largest extent entry\n  - sanity_check_extent_cache\n  : access et-\u003elargest w/o lock\n\nlet's refactor sanity_check_extent_cache() to avoid extent cache access\nand call it before f2fs_init_read_extent_tree() to fix this issue.","modified":"2026-03-20T12:38:54.307785Z","published":"2024-08-26T11:20:45.678Z","related":["MGASA-2024-0309","MGASA-2024-0310"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/44xxx/CVE-2024-44941.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/263df78166d3a9609b97d28c34029bd01874cbb8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/323ef20b5558b9d9fd10c1224327af6f11a8177d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d7409b05a64f212735f0d33f5f1602051a886eab"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/44xxx/CVE-2024-44941.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-44941"},{"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":"98e4da8ca301e062d79ae168c67e56f3c3de3ce4"},{"fixed":"263df78166d3a9609b97d28c34029bd01874cbb8"},{"fixed":"323ef20b5558b9d9fd10c1224327af6f11a8177d"},{"fixed":"d7409b05a64f212735f0d33f5f1602051a886eab"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-44941.json"}}],"schema_version":"1.7.5"}