CVE-2025-37947: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-37947 is a vulnerability discovered in the Linux kernel's ksmbd filesystem component, specifically affecting the ksmbd_vfs_stream_write() function. The vulnerability was disclosed on May 20, 2025, and affects various Linux distributions including Debian and Ubuntu systems (NVD, Wiz).

The vulnerability stems from a missing bounds check in the ksmbd_vfs_stream_write() function. The function failed to validate whether the write offset (*pos) was within the bounds of the existing stream data length (v_len). When *pos was greater than or equal to v_len, it could result in an out-of-bounds memory write. The issue has been assigned a CVSS v3.1 base score of 5.5 with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (RedHat, Wiz).

If successfully exploited, this vulnerability could lead to out-of-bounds memory writes in the Linux kernel, potentially resulting in memory corruption, system crashes, or privilege escalation (Wiz).

The vulnerability has been patched by adding a validation check for the write offset in ksmbd_vfs_stream_write(). The fix ensures that *pos is less than v_len before proceeding with the write operation, returning -EINVAL if the condition fails. For Debian's stable distribution (bookworm), these problems have been fixed in version 6.1.140-1 (Debian).