CVE-2024-50278: Linux kernel · dm cache: fix potential out-of-bounds access on the first resume
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 potential out-of-bounds access on the first resume Out-of-bounds access occurs if the fast device is expanded unexpectedly before the first-time resume of the cache table. This happens because expanding the fast device requires reloading the cache table for cache_create to allocate new in-core data structures that fit the new size, and the check in cache_preresume is not performed during the first resume, leading to the issue. Reproduce steps: 1. prepare component devices: dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 65536 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 2. load a cache table of 512 cache blocks, and deliberately expand the fast device before resuming the cache, making the in-core data structures inadequate. dmsetup create cache --notable dmsetup reload cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" dmsetup reload cdata --table "0 131072 linear /dev/sdc 8192" dmsetup resume cdata dmsetup resume cache 3. suspend the cache to write out the in-core dirty bitset and hint array, leading to out-of-bounds access to the dirty bitset at offset 0x40: dmsetup suspend cache KASAN reports: BUG: KASAN: vmalloc-out-of-bounds in is_dirty_callback+0x2b/0x80 Read of size 8 at addr ffffc90000085040 by task dmsetup/90 (...snip...) The buggy address belongs to the virtual mapping at [ffffc90000085000, ffffc90000087000) created by: cache_ctr+0x176a/0x35f0 (...snip...) Memory state around the buggy address: ffffc90000084f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90000084f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffffc90000085000: 00 00 00 00 00 00 00 00 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc90000085080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc90000085100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 Fix by checking the size change on the first resume.
References
- ubuntu.com/security/CVE-2024-50278 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-50278 (opens in a new tab)
- git.kernel.org/linus/c0ade5d98979585d4f5a93e4514c2e9a65afa08d (opens in a new tab)
- git.kernel.org/stable/c/e492f71854ce03474d49e87fd98b8df1f7cd1d2d (opens in a new tab)
- git.kernel.org/stable/c/2222b0929d00e2d13732b799b63be391b5de4492 (opens in a new tab)
- git.kernel.org/stable/c/483b7261b35a9d369082ab298a6670912243f0be (opens in a new tab)
- git.kernel.org/stable/c/fdef3b94dfebd57e3077a578b6e309a2bb6fa688 (opens in a new tab)
- git.kernel.org/stable/c/c52ec00cb2f9bebfada22edcc0db385b910a1cdb (opens in a new tab)
- git.kernel.org/stable/c/036dd6e3d2638103e0092864577ea1d091466b86 (opens in a new tab)
- git.kernel.org/stable/c/13ed3624c6ef283acefa4cc42cc8ae54fd4391a4 (opens in a new tab)
- git.kernel.org/stable/c/c0ade5d98979585d4f5a93e4514c2e9a65afa08d (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)