CVE-2024-40913
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.29% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/4b4391e77a6bf24cba2ef1590e113d9b73b11039Patch
- https://git.kernel.org/stable/c/b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32Patch
- https://git.kernel.org/stable/c/d2d3eb377a5d081bf2bed177d354a4f59b74da88Patch
- https://git.kernel.org/stable/c/eac51d9daacd61dcc93333ff6a890cf3efc8c1c0Patch
- https://git.kernel.org/stable/c/4b4391e77a6bf24cba2ef1590e113d9b73b11039Patch
- https://git.kernel.org/stable/c/b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32Patch
- https://git.kernel.org/stable/c/d2d3eb377a5d081bf2bed177d354a4f59b74da88Patch
- https://git.kernel.org/stable/c/eac51d9daacd61dcc93333ff6a890cf3efc8c1c0Patch
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.