CVE-2024-50279

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Source
https://nvd.nist.gov/vuln/detail/CVE-2024-50279
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-50279.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2024-50279
Downstream
Related
Published
2024-11-19T01:30:20.712Z
Modified
2025-11-28T02:34:35.371848Z
Severity
  • 7.1 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H CVSS Calculator
Summary
dm cache: fix out-of-bounds access to the dirty bitset when resizing
Details

In the Linux kernel, the following vulnerability has been resolved:

dm cache: fix out-of-bounds access to the dirty bitset when resizing

dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access.

Reproduce steps:

  1. create a cache device of 1024 cache blocks (128 bytes dirty bitset)

dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"

  1. shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80)

dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache

KASAN reports:

BUG: KASAN: vmalloc-out-of-bounds in cache_preresume+0x269/0x7b0 Read of size 8 at addr ffffc900000f3080 by task dmsetup/131

(...snip...) The buggy address belongs to the virtual mapping at [ffffc900000f3000, ffffc900000f5000) created by: cache_ctr+0x176a/0x35f0

(...snip...) Memory state around the buggy address: ffffc900000f2f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

ffffc900000f3080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900000f3100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900000f3180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8

Fix by making the index post-incremented.

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/50xxx/CVE-2024-50279.json"
}
References

Affected packages

Git / 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
f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498
Fixed
4fa4feb873cea0e9d6ff883b37cca6f33169d8b4
Fixed
8501e38dc9e0060814c4085815fc83da3e6d43bf
Fixed
ee1f74925717ab36f6a091104c170639501ce818
Fixed
ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f
Fixed
56507203e1b6127967ec2b51fb0b23a0d4af1334
Fixed
e57648ce325fa405fe6bbd0e6a618ced7c301a2d
Fixed
3b02c40ff10fdf83cc545850db208de855ebe22c
Fixed
792227719725497ce10a8039803bec13f89f8910

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
3.13.0
Fixed
4.19.324
Type
ECOSYSTEM
Events
Introduced
4.20.0
Fixed
5.4.286
Type
ECOSYSTEM
Events
Introduced
5.5.0
Fixed
5.10.230
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.172
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.117
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.61
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.11.8