cbcvebase.
CVE-2024-56565
published 2024-12-27

CVE-2024-56565: In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to drop all discards after creating snapshot on lvm device Piergiorgio reported a…

PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.22%
12.1th percentile
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to drop all discards after creating snapshot on lvm device Piergiorgio reported a bug in bugzilla as below: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 969 at fs/f2fs/segment.c:1330 RIP: 0010:__submit_discard_cmd+0x27d/0x400 [f2fs] Call Trace: __issue_discard_cmd+0x1ca/0x350 [f2fs] issue_discard_thread+0x191/0x480 [f2fs] kthread+0xcf/0x100 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 w/ below testcase, it can reproduce this bug quickly: - pvcreate /dev/vdb - vgcreate myvg1 /dev/vdb - lvcreate -L 1024m -n mylv1 myvg1 - mount /dev/myvg1/mylv1 /mnt/f2fs - dd if=/dev/zero of=/mnt/f2fs/file bs=1M count=20 - sync - rm /mnt/f2fs/file - sync - lvcreate -L 1024m -s -n mylv1-snapshot /dev/myvg1/mylv1 - umount /mnt/f2fs The root cause is: it will update discard_max_bytes of mounted lvm device to zero after creating snapshot on this lvm device, then, __submit_discard_cmd() will pass parameter @nr_sects w/ zero value to __blkdev_issue_discard(), it returns a NULL bio pointer, result in panic. This patch changes as below for fixing: 1. Let's drop all remained discards in f2fs_unfreeze() if snapshot of lvm device is created. 2. Checking discard_max_bytes before submitting discard during __submit_discard_cmd().

Affected

11 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.12.5-1 (forky)linux 6.12.5-1 (forky)
linuxlinux
linuxlinux>= 35ec7d5748849762008e8ae9f8ad2766229d5794 < ed24ab98242f8d22b66fbe0452c97751b5ea4e22ed24ab98242f8d22b66fbe0452c97751b5ea4e22
linuxlinux>= 35ec7d5748849762008e8ae9f8ad2766229d5794 < 15136c3861a3341db261ebdbb6ae4ae1765635e215136c3861a3341db261ebdbb6ae4ae1765635e2
linuxlinux>= 35ec7d5748849762008e8ae9f8ad2766229d5794 < bc8aeb04fd80cb8cfae3058445c84410fd0beb5ebc8aeb04fd80cb8cfae3058445c84410fd0beb5e
linuxlinux_kernel>= 0 < 6.12.5-16.12.5-1
linuxlinux_kernel>= 0 < 6.12.5-16.12.5-1
linuxlinux_kernel>= 0 < 6.8.0-58.606.8.0-58.60
linuxlinux_kernel>= 4.19 < 6.6.666.6.66
linuxlinux_kernel>= 6.7 < 6.12.46.12.4
msrccbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv8.8HIGH
vendor_ubuntu8.8HIGH
vendor_debian5.5MEDIUM
vendor_msrc5.5MEDIUM
vendor_redhat5.5MEDIUM
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