NVD Vulnerability Detail
Search Exploit, PoC
CVE-2024-47680
Summary

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.

Publication Date Oct. 21, 2024, 9:15 p.m.
Registration Date Oct. 22, 2024, 5:01 a.m.
Last Update Oct. 24, 2024, 10:28 p.m.
CVSS3.1 : MEDIUM
スコア 5.5
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
攻撃元区分(AV) ローカル
攻撃条件の複雑さ(AC)
攻撃に必要な特権レベル(PR)
利用者の関与(UI) 不要
影響の想定範囲(S) 変更なし
機密性への影響(C) なし
完全性への影響(I) なし
可用性への影響(A)
Affected software configurations
Configuration1 or higher or less more than less than
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.11 6.11.2
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.10 6.10.13
Related information, measures and tools
Common Vulnerabilities List

JVN Vulnerability Information
Linux の Linux Kernel における NULL ポインタデリファレンスに関する脆弱性
Title Linux の Linux Kernel における NULL ポインタデリファレンスに関する脆弱性
Summary

Linux の Linux Kernel には、NULL ポインタデリファレンスに関する脆弱性が存在します。

Possible impacts サービス運用妨害 (DoS) 状態にされる可能性があります。 
Solution

ベンダより正式な対策が公開されています。ベンダ情報を参照して適切な対策を実施してください。

Publication Date Aug. 21, 2024, midnight
Registration Date Oct. 29, 2024, 2:10 p.m.
Last Update Oct. 29, 2024, 2:10 p.m.
Affected System
Linux
Linux Kernel 6.10 以上 6.10.13 未満
Linux Kernel 6.11 以上 6.11.2 未満
CVE (情報セキュリティ 共通脆弱性識別子)
CWE (共通脆弱性タイプ一覧)
ベンダー情報
Change Log
No Changed Details Date of change
1 [2024年10月29日]
  掲載
Oct. 29, 2024, 2:10 p.m.