{"id":"DEBIAN-CVE-2022-50344","details":"In the Linux kernel, the following vulnerability has been resolved:  ext4: fix null-ptr-deref in ext4_write_info  I caught a null-ptr-deref bug as follows: ================================================================== KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339 RIP: 0010:ext4_write_info+0x53/0x1b0 [...] Call Trace:  dquot_writeback_dquots+0x341/0x9a0  ext4_sync_fs+0x19e/0x800  __sync_filesystem+0x83/0x100  sync_filesystem+0x89/0xf0  generic_shutdown_super+0x79/0x3e0  kill_block_super+0xa1/0x110  deactivate_locked_super+0xac/0x130  deactivate_super+0xb6/0xd0  cleanup_mnt+0x289/0x400  __cleanup_mnt+0x16/0x20  task_work_run+0x11c/0x1c0  exit_to_user_mode_prepare+0x203/0x210  syscall_exit_to_user_mode+0x5b/0x3a0  do_syscall_64+0x59/0x70  entry_SYSCALL_64_after_hwframe+0x44/0xa9  ==================================================================  Above issue may happen as follows: ------------------------------------- exit_to_user_mode_prepare  task_work_run   __cleanup_mnt    cleanup_mnt     deactivate_super      deactivate_locked_super       kill_block_super        generic_shutdown_super         shrink_dcache_for_umount          dentry = sb-\u003es_root          sb-\u003es_root = NULL              \u003c--- Here set NULL         sync_filesystem          __sync_filesystem           sb-\u003es_op-\u003esync_fs \u003e ext4_sync_fs            dquot_writeback_dquots             sb-\u003edq_op-\u003ewrite_info \u003e ext4_write_info              ext4_journal_start(d_inode(sb-\u003es_root), EXT4_HT_QUOTA, 2)               d_inode(sb-\u003es_root)                s_root-\u003ed_inode          \u003c--- Null pointer dereference  To solve this problem, we use ext4_journal_start_sb directly to avoid s_root being used.","modified":"2026-09-01T20:04:58.410116987Z","published":"2025-09-16T17:15:34.070Z","upstream":["CVE-2022-50344"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-50344"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50344.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50344.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.3-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2022-50344.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:N/I:N/A:H"}]}