{"id":"DEBIAN-CVE-2022-50638","details":"In the Linux kernel, the following vulnerability has been resolved:  ext4: fix bug_on in __es_tree_search caused by bad boot loader inode  We got a issue as fllows: ==================================================================  kernel BUG at fs/ext4/extents_status.c:203!  invalid opcode: 0000 [#1] PREEMPT SMP  CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349  RIP: 0010:ext4_es_end.isra.0+0x34/0x42  RSP: 0018:ffffc9000143b768 EFLAGS: 00010203  RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000  RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff  RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8  R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0  R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000  FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033  CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400  Call Trace:   \u003cTASK\u003e   __es_tree_search.isra.0+0x6d/0xf5   ext4_es_cache_extent+0xfa/0x230   ext4_cache_extents+0xd2/0x110   ext4_find_extent+0x5d5/0x8c0   ext4_ext_map_blocks+0x9c/0x1d30   ext4_map_blocks+0x431/0xa50   ext4_mpage_readpages+0x48e/0xe40   ext4_readahead+0x47/0x50   read_pages+0x82/0x530   page_cache_ra_unbounded+0x199/0x2a0   do_page_cache_ra+0x47/0x70   page_cache_ra_order+0x242/0x400   ondemand_readahead+0x1e8/0x4b0   page_cache_sync_ra+0xf4/0x110   filemap_get_pages+0x131/0xb20   filemap_read+0xda/0x4b0   generic_file_read_iter+0x13a/0x250   ext4_file_read_iter+0x59/0x1d0   vfs_read+0x28f/0x460   ksys_read+0x73/0x160   __x64_sys_read+0x1e/0x30   do_syscall_64+0x35/0x80   entry_SYSCALL_64_after_hwframe+0x63/0xcd   \u003c/TASK\u003e ==================================================================  In the above issue, ioctl invokes the swap_inode_boot_loader function to swap inode\u003c5\u003e and inode\u003c12\u003e. However, inode\u003c5\u003e contain incorrect imode and disordered extents, and i_nlink is set to 1. The extents check for inode in the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO. While links_count is set to 1, the extents are not initialized in swap_inode_boot_loader. After the ioctl command is executed successfully, the extents are swapped to inode\u003c12\u003e, in this case, run the `cat` command to view inode\u003c12\u003e. And Bug_ON is triggered due to the incorrect extents.  When the boot loader inode is not initialized, its imode can be one of the following: 1) the imode is a bad type, which is marked as bad_inode in ext4_iget and    set to S_IFREG. 2) the imode is good type but not S_IFREG. 3) the imode is S_IFREG.  The BUG_ON may be triggered by bypassing the check in cases 1 and 2. Therefore, when the boot loader inode is bad_inode or its imode is not S_IFREG, initialize the inode to avoid triggering the BUG.","modified":"2026-09-01T16:05:35.877872915Z","published":"2025-12-09T01:16:46.120Z","upstream":["CVE-2022-50638"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-50638"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50638.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50638.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.4-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50638.json"}}],"schema_version":"1.9.0"}