CVE - CVE-2024-47680

CVE-ID
CVE-2024-47680	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
Description
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/43aec4d01bd2ce961817a777b3846f8318f398e4 URL:https://git.kernel.org/stable/c/43aec4d01bd2ce961817a777b3846f8318f398e4 MISC:https://git.kernel.org/stable/c/7bd7ce68ddad5a28565e42ef21cacaff113773a9 URL:https://git.kernel.org/stable/c/7bd7ce68ddad5a28565e42ef21cacaff113773a9 MISC:https://git.kernel.org/stable/c/d2352b57897f6a3349666fc318dcbec99092c6a5 URL:https://git.kernel.org/stable/c/d2352b57897f6a3349666fc318dcbec99092c6a5
Assigning CNA
kernel.org
Date Record Created
20240930	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240930)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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