CVE-2024-26840: Linux kernel · cachefiles: fix memory leak in cachefiles_add_cache()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 4.4.0-1134.140 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 4.4.0-1134.140, 4.15.0-1179.194~14.04.1, 4.4.0-257.291~14.04.1 +78
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Apr 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-6820-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6831-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6867-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6871-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6892-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6919-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther 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: cachefiles: fix memory leak in cachefiles_add_cache() The following memory leak was reported after unbinding /dev/cachefiles: ================================================================== unreferenced object 0xffff9b674176e3c0 (size 192): comm "cachefilesd2", pid 680, jiffies 4294881224 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc ea38a44b): [<ffffffff8eb8a1a5>] kmem_cache_alloc+0x2d5/0x370 [<ffffffff8e917f86>] prepare_creds+0x26/0x2e0 [<ffffffffc002eeef>] cachefiles_determine_cache_security+0x1f/0x120 [<ffffffffc00243ec>] cachefiles_add_cache+0x13c/0x3a0 [<ffffffffc0025216>] cachefiles_daemon_write+0x146/0x1c0 [<ffffffff8ebc4a3b>] vfs_write+0xcb/0x520 [<ffffffff8ebc5069>] ksys_write+0x69/0xf0 [<ffffffff8f6d4662>] do_syscall_64+0x72/0x140 [<ffffffff8f8000aa>] entry_SYSCALL_64_after_hwframe+0x6e/0x76 ================================================================== Put the reference count of cache_cred in cachefiles_daemon_unbind() to fix the problem. And also put cache_cred in cachefiles_add_cache() error branch to avoid memory leaks.
References
- ubuntu.com/security/CVE-2024-26840 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26840 (opens in a new tab)
- git.kernel.org/linus/e21a2f17566cbd64926fb8f16323972f7a064444 (opens in a new tab)
- git.kernel.org/stable/c/cb5466783793e66272624cf71925ae1d1ba32083 (opens in a new tab)
- git.kernel.org/stable/c/037d5a949b0455540ef9aab34c10ddf54b65d285 (opens in a new tab)
- git.kernel.org/stable/c/43eccc5823732ba6daab2511ed32dfc545a666d8 (opens in a new tab)
- git.kernel.org/stable/c/94965be37add0983672e48ecb33cdbda92b62579 (opens in a new tab)
- git.kernel.org/stable/c/8b218e2f0a27a9f09428b1847b4580640b9d1e58 (opens in a new tab)
- git.kernel.org/stable/c/38e921616320d159336b0ffadb09e9fb4945c7c3 (opens in a new tab)
- git.kernel.org/stable/c/9cac69912052a4def571fedf1cb9bb4ec590e25a (opens in a new tab)
- git.kernel.org/stable/c/e21a2f17566cbd64926fb8f16323972f7a064444 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6820-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6831-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6821-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6867-1 (opens in a new tab)