CVE-2024-40913: Linux kernel · cachefiles: defer exposing anon_fd until after copy_to_user() succeeds
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 29 Oct 2026, 22:52 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: cachefiles: defer exposing anon_fd until after copy_to_user() succeeds After installing the anonymous fd, we can now see it in userland and close it. However, at this point we may not have gotten the reference count of the cache, but we will put it during colse fd, so this may cause a cache UAF. So grab the cache reference count before fd_install(). In addition, by kernel convention, fd is taken over by the user land after fd_install(), and the kernel should not call close_fd() after that, i.e., it should call fd_install() after everything is ready, thus fd_install() is called after copy_to_user() succeeds.
References
- nvd.nist.gov/vuln/detail/CVE-2024-40913 (opens in a new tab)
- git.kernel.org/stable/c/4b4391e77a6bf24cba2ef1590e113d9b73b11039 (opens in a new tab)
- git.kernel.org/stable/c/b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32 (opens in a new tab)
- git.kernel.org/stable/c/d2d3eb377a5d081bf2bed177d354a4f59b74da88 (opens in a new tab)
- git.kernel.org/stable/c/eac51d9daacd61dcc93333ff6a890cf3efc8c1c0 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/01/msg00001.html (opens in a new tab)