{"id":"CVE-2022-48631","summary":"ext4: fix bug in extents parsing when eh_entries == 0 and eh_depth \u003e 0","details":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix bug in extents parsing when eh_entries == 0 and eh_depth \u003e 0\n\nWhen walking through an inode extents, the ext4_ext_binsearch_idx() function\nassumes that the extent header has been previously validated.  However, there\nare no checks that verify that the number of entries (eh-\u003eeh_entries) is\nnon-zero when depth is \u003e 0.  And this will lead to problems because the\nEXT_FIRST_INDEX() and EXT_LAST_INDEX() will return garbage and result in this:\n\n[  135.245946] ------------[ cut here ]------------\n[  135.247579] kernel BUG at fs/ext4/extents.c:2258!\n[  135.249045] invalid opcode: 0000 [#1] PREEMPT SMP\n[  135.250320] CPU: 2 PID: 238 Comm: tmp118 Not tainted 5.19.0-rc8+ #4\n[  135.252067] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014\n[  135.255065] RIP: 0010:ext4_ext_map_blocks+0xc20/0xcb0\n[  135.256475] Code:\n[  135.261433] RSP: 0018:ffffc900005939f8 EFLAGS: 00010246\n[  135.262847] RAX: 0000000000000024 RBX: ffffc90000593b70 RCX: 0000000000000023\n[  135.264765] RDX: ffff8880038e5f10 RSI: 0000000000000003 RDI: ffff8880046e922c\n[  135.266670] RBP: ffff8880046e9348 R08: 0000000000000001 R09: ffff888002ca580c\n[  135.268576] R10: 0000000000002602 R11: 0000000000000000 R12: 0000000000000024\n[  135.270477] R13: 0000000000000000 R14: 0000000000000024 R15: 0000000000000000\n[  135.272394] FS:  00007fdabdc56740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000\n[  135.274510] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  135.276075] CR2: 00007ffc26bd4f00 CR3: 0000000006261004 CR4: 0000000000170ea0\n[  135.277952] Call Trace:\n[  135.278635]  \u003cTASK\u003e\n[  135.279247]  ? preempt_count_add+0x6d/0xa0\n[  135.280358]  ? percpu_counter_add_batch+0x55/0xb0\n[  135.281612]  ? _raw_read_unlock+0x18/0x30\n[  135.282704]  ext4_map_blocks+0x294/0x5a0\n[  135.283745]  ? xa_load+0x6f/0xa0\n[  135.284562]  ext4_mpage_readpages+0x3d6/0x770\n[  135.285646]  read_pages+0x67/0x1d0\n[  135.286492]  ? folio_add_lru+0x51/0x80\n[  135.287441]  page_cache_ra_unbounded+0x124/0x170\n[  135.288510]  filemap_get_pages+0x23d/0x5a0\n[  135.289457]  ? path_openat+0xa72/0xdd0\n[  135.290332]  filemap_read+0xbf/0x300\n[  135.291158]  ? _raw_spin_lock_irqsave+0x17/0x40\n[  135.292192]  new_sync_read+0x103/0x170\n[  135.293014]  vfs_read+0x15d/0x180\n[  135.293745]  ksys_read+0xa1/0xe0\n[  135.294461]  do_syscall_64+0x3c/0x80\n[  135.295284]  entry_SYSCALL_64_after_hwframe+0x46/0xb0\n\nThis patch simply adds an extra check in __ext4_ext_check(), verifying that\neh_entries is not 0 when eh_depth is \u003e 0.","modified":"2026-04-02T08:26:41.871675Z","published":"2024-04-28T12:59:06.569Z","related":["SUSE-SU-2024:1641-1","SUSE-SU-2024:1642-1","SUSE-SU-2024:1644-1","SUSE-SU-2024:1645-1","SUSE-SU-2024:1647-1","SUSE-SU-2024:1650-1","SUSE-SU-2024:1659-1","SUSE-SU-2024:1663-1","SUSE-SU-2025:4189-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48631.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/29a5b8a137ac8eb410cc823653a29ac0e7b7e1b0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2f5e9de15e4f55fbf56f22d4a2ce406246cc462d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/958b0ee23f5ac106e7cc11472b71aa2ea9a033bc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bb7eb3ca4b3b0d2c7872cf1a41c30f5e5bd65df0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be4df018c0be5ebecf1ca510feacc23be415cefc"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48631.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-48631"},{"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":"c29c0ae7f282828da3695167ed870131798348d9"},{"fixed":"bb7eb3ca4b3b0d2c7872cf1a41c30f5e5bd65df0"},{"fixed":"958b0ee23f5ac106e7cc11472b71aa2ea9a033bc"},{"fixed":"be4df018c0be5ebecf1ca510feacc23be415cefc"},{"fixed":"2f5e9de15e4f55fbf56f22d4a2ce406246cc462d"},{"fixed":"29a5b8a137ac8eb410cc823653a29ac0e7b7e1b0"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48631.json"}}],"schema_version":"1.7.5"}