cbcvebase.
CVE-2024-47680
published 2024-10-21

CVE-2024-47680: In the Linux kernel, the following vulnerability has been resolved: f2fs: check discard support for conventional zones As the helper function…

PriorityP420medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.23%
14.1th percentile
In the Linux kernel, the following vulnerability has been resolved: f2fs: check discard support for conventional zones As the helper function f2fs_bdev_support_discard() shows, f2fs checks if the target block devices support discard by calling bdev_max_discard_sectors() and bdev_is_zoned(). This check works well for most cases, but it does not work for conventional zones on zoned block devices. F2fs assumes that zoned block devices support discard, and calls __submit_discard_cmd(). When __submit_discard_cmd() is called for sequential write required zones, it works fine since __submit_discard_cmd() issues zone reset commands instead of discard commands. However, when __submit_discard_cmd() is called for conventional zones, __blkdev_issue_discard() is called even when the devices do not support discard. The inappropriate __blkdev_issue_discard() call was not a problem before the commit 30f1e7241422 ("block: move discard checks into the ioctl handler") because __blkdev_issue_discard() checked if the target devices support discard or not. If not, it returned EOPNOTSUPP. After the commit, __blkdev_issue_discard() no longer checks it. It always returns zero and sets NULL to the given bio pointer. This NULL pointer triggers f2fs_bug_on() in __submit_discard_cmd(). The BUG is recreated with the commands below at the umount step, where /dev/nullb0 is a zoned null_blk with 5GB total size, 128MB zone size and 10 conventional zones. $ mkfs.f2fs -f -m /dev/nullb0 $ mount /dev/nullb0 /mnt $ for ((i=0;i<5;i++)); do dd if=/dev/zero of=/mnt/test bs=65536 count=1600 conv=fsync; done $ umount /mnt To fix the BUG, avoid the inappropriate __blkdev_issue_discard() call. When discard is requested for conventional zones, check if the device supports discard or not. If not, return EOPNOTSUPP.

Affected

10 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.11.2-1 (forky)linux 6.11.2-1 (forky)
linuxlinux
linuxlinux>= 30f1e724142242a453f92d90b33e030014900bf0 < 7bd7ce68ddad5a28565e42ef21cacaff113773a97bd7ce68ddad5a28565e42ef21cacaff113773a9
linuxlinux>= 30f1e724142242a453f92d90b33e030014900bf0 < d2352b57897f6a3349666fc318dcbec99092c6a5d2352b57897f6a3349666fc318dcbec99092c6a5
linuxlinux>= 30f1e724142242a453f92d90b33e030014900bf0 < 43aec4d01bd2ce961817a777b3846f8318f398e443aec4d01bd2ce961817a777b3846f8318f398e4
linuxlinux_kernel>= 0 < 6.11.2-16.11.2-1
linuxlinux_kernel>= 0 < 6.11.2-16.11.2-1
linuxlinux_kernel>= 0 < 6.11.0-18.186.11.0-18.18
linuxlinux_kernel>= 6.10 < 6.10.136.10.13
linuxlinux_kernel>= 6.11 < 6.11.26.11.2

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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