CVE-2025-21994

ksmbd: fix incorrect validation for num_aces field of smb_acl

EPSS 0.2%

Vexday Risk Score

3Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS —EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

02 Apr 2025Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix incorrect validation for num_aces field of smb_acl parse_dcal() validate num_aces to allocate posix_ace_state_array. if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) It is an incorrect validation that we can create an array of size ULONG_MAX. smb_acl has ->size field to calculate actual number of aces in request buffer size. Use this to check invalid num_aces.

Affected products

Linux · Linux

References

https://git.kernel.org/stable/c/1b8b67f3c5e5169535e26efedd3e422172e2db64 https://git.kernel.org/stable/c/9c4e202abff45f8eac17989e549fc7a75095f675 https://git.kernel.org/stable/c/a4cb17797a5d241f1e509cb5b46ed95a80c2f5fd https://git.kernel.org/stable/c/c3a3484d9d31b27a3db0fab91fcf191132d65236 https://git.kernel.org/stable/c/d0f87370622a853b57e851f7d5a5452b72300f19 https://git.kernel.org/stable/c/f6a6721802ac2f12f4c1bbe839a4c229b61866f2 https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html