CVE-2024-50279: Linux kernel · dm cache: fix out-of-bounds access to the dirty bitset when resizing dm-cache checks
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High · fixed in 5.4.0-1142.152~18.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:13 UTC
- Patch
- Available – fixed in 5.4.0-1142.152~18.04.1, 5.4.0-1145.152~18.04.1, 5.4.0-1143.152~18.04.1 +84
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Nov 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7291-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7293-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7294-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7295-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7305-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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" 2. 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.
References
- ubuntu.com/security/CVE-2024-50279 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-50279 (opens in a new tab)
- git.kernel.org/linus/792227719725497ce10a8039803bec13f89f8910 (opens in a new tab)
- git.kernel.org/stable/c/4fa4feb873cea0e9d6ff883b37cca6f33169d8b4 (opens in a new tab)
- git.kernel.org/stable/c/8501e38dc9e0060814c4085815fc83da3e6d43bf (opens in a new tab)
- git.kernel.org/stable/c/ee1f74925717ab36f6a091104c170639501ce818 (opens in a new tab)
- git.kernel.org/stable/c/ff1dd8a04c30e8d4e2fd5c83198ca672eb6a9e7f (opens in a new tab)
- git.kernel.org/stable/c/56507203e1b6127967ec2b51fb0b23a0d4af1334 (opens in a new tab)
- git.kernel.org/stable/c/e57648ce325fa405fe6bbd0e6a618ced7c301a2d (opens in a new tab)
- git.kernel.org/stable/c/3b02c40ff10fdf83cc545850db208de855ebe22c (opens in a new tab)
- git.kernel.org/stable/c/792227719725497ce10a8039803bec13f89f8910 (opens in a new tab)
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7291-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7293-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7294-1 (opens in a new tab)