CVE-2025-21964

In the Linux kernel, the following vulnerability has been resolved:

cifs: Fix integer overflow while processing acregmax mount option

User-provided mount parameter acregmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Red Hat rates this vulnerability as Moderate impact because exploiting it requires local privileges to mount network filesystems, restricting the threat scope to authenticated users and limiting the consequence to denial of service without compromising host data confidentiality or integrity. CIFS shares are not mounted by default, and unprivileged users typically lack the permissions necessary to supply custom filesystem parameters. Consequently, typical enterprise installations are exposed only if untrusted local users have delegated mount capabilities or containerized administrative privileges.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.