{"id":"CVE-2024-56565","summary":"f2fs: fix to drop all discards after creating snapshot on lvm device","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to drop all discards after creating snapshot on lvm device\n\nPiergiorgio reported a bug in bugzilla as below:\n\n------------[ cut here ]------------\nWARNING: CPU: 2 PID: 969 at fs/f2fs/segment.c:1330\nRIP: 0010:__submit_discard_cmd+0x27d/0x400 [f2fs]\nCall Trace:\n __issue_discard_cmd+0x1ca/0x350 [f2fs]\n issue_discard_thread+0x191/0x480 [f2fs]\n kthread+0xcf/0x100\n ret_from_fork+0x31/0x50\n ret_from_fork_asm+0x1a/0x30\n\nw/ below testcase, it can reproduce this bug quickly:\n- pvcreate /dev/vdb\n- vgcreate myvg1 /dev/vdb\n- lvcreate -L 1024m -n mylv1 myvg1\n- mount /dev/myvg1/mylv1 /mnt/f2fs\n- dd if=/dev/zero of=/mnt/f2fs/file bs=1M count=20\n- sync\n- rm /mnt/f2fs/file\n- sync\n- lvcreate -L 1024m -s -n mylv1-snapshot /dev/myvg1/mylv1\n- umount /mnt/f2fs\n\nThe root cause is: it will update discard_max_bytes of mounted lvm\ndevice to zero after creating snapshot on this lvm device, then,\n__submit_discard_cmd() will pass parameter @nr_sects w/ zero value\nto __blkdev_issue_discard(), it returns a NULL bio pointer, result\nin panic.\n\nThis patch changes as below for fixing:\n1. Let's drop all remained discards in f2fs_unfreeze() if snapshot\nof lvm device is created.\n2. Checking discard_max_bytes before submitting discard during\n__submit_discard_cmd().","modified":"2026-04-24T06:42:50.482436669Z","published":"2024-12-27T14:23:09.350Z","related":["USN-7379-2","USN-7380-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56565.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/15136c3861a3341db261ebdbb6ae4ae1765635e2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bc8aeb04fd80cb8cfae3058445c84410fd0beb5e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ed24ab98242f8d22b66fbe0452c97751b5ea4e22"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56565.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-56565"},{"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":"35ec7d5748849762008e8ae9f8ad2766229d5794"},{"fixed":"ed24ab98242f8d22b66fbe0452c97751b5ea4e22"},{"fixed":"15136c3861a3341db261ebdbb6ae4ae1765635e2"},{"fixed":"bc8aeb04fd80cb8cfae3058445c84410fd0beb5e"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56565.json"}}],"schema_version":"1.7.5"}