{"id":"DEBIAN-CVE-2022-50021","details":"In the Linux kernel, the following vulnerability has been resolved:  ext4: block range must be validated before use in ext4_mb_clear_bb()  Block range to free is validated in ext4_free_blocks() using ext4_inode_block_valid() and then it's passed to ext4_mb_clear_bb(). However in some situations on bigalloc file system the range might be adjusted after the validation in ext4_free_blocks() which can lead to troubles on corrupted file systems such as one found by syzkaller that resulted in the following BUG  kernel BUG at fs/ext4/ext4.h:3319! PREEMPT SMP NOPTI CPU: 28 PID: 4243 Comm: repro Kdump: loaded Not tainted 5.19.0-rc6+ #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 RIP: 0010:ext4_free_blocks+0x95e/0xa90 Call Trace:  \u003cTASK\u003e  ? lock_timer_base+0x61/0x80  ? __es_remove_extent+0x5a/0x760  ? __mod_timer+0x256/0x380  ? ext4_ind_truncate_ensure_credits+0x90/0x220  ext4_clear_blocks+0x107/0x1b0  ext4_free_data+0x15b/0x170  ext4_ind_truncate+0x214/0x2c0  ? _raw_spin_unlock+0x15/0x30  ? ext4_discard_preallocations+0x15a/0x410  ? ext4_journal_check_start+0xe/0x90  ? __ext4_journal_start_sb+0x2f/0x110  ext4_truncate+0x1b5/0x460  ? __ext4_journal_start_sb+0x2f/0x110  ext4_evict_inode+0x2b4/0x6f0  evict+0xd0/0x1d0  ext4_enable_quotas+0x11f/0x1f0  ext4_orphan_cleanup+0x3de/0x430  ? proc_create_seq_private+0x43/0x50  ext4_fill_super+0x295f/0x3ae0  ? snprintf+0x39/0x40  ? sget_fc+0x19c/0x330  ? ext4_reconfigure+0x850/0x850  get_tree_bdev+0x16d/0x260  vfs_get_tree+0x25/0xb0  path_mount+0x431/0xa70  __x64_sys_mount+0xe2/0x120  do_syscall_64+0x5b/0x80  ? do_user_addr_fault+0x1e2/0x670  ? exc_page_fault+0x70/0x170  entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fdf4e512ace  Fix it by making sure that the block range is properly validated before used every time it changes in ext4_free_blocks() or ext4_mb_clear_bb().","modified":"2026-09-01T16:05:34.000369463Z","published":"2025-06-18T11:15:30.280Z","upstream":["CVE-2022-50021"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-50021"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50021.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50021.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.2-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50021.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}