Executive brief
A vulnerability was identified in the Linux kernel's ksmbd component, which provides SMB file sharing services. Under certain error conditions during file link creation, the system fails to properly release internal locks. This can lead to a system deadlock, potentially causing the file sharing service or the entire system to become unresponsive, impacting business operations and data availability.
Technical details
A resource management vulnerability exists in the ksmbd module of the Linux kernel. Specifically, in the 'smb2_create_link' function, the kernel fails to call 'ksmbd_vfs_kern_path_end_removing()' (or its equivalent 'ksmbd_vfs_kern_path_unlock()') on certain error paths. This results in unbalanced inode locks and leaked references when a link creation fails due to an existing link or deletion errors. An attacker or a series of malformed requests could trigger these error paths to cause a kernel deadlock or workqueue lock leak, leading to a Denial of Service (DoS). The issue has been resolved by ensuring proper lock release before exiting the affected functions.
Affected products
- Linux Linux Kernel 6.1.162 and other stable branches
Timeline
- 2026-02-24: other: Vulnerability fixed in upstream commits
- 2026-05-27: advisory: CVE-2026-45924 published by kernel.org
References
- https://git.kernel.org/stable/c/0c578e8065c4b08d5635a4cbc0f6321df9d20f79
- https://git.kernel.org/stable/c/34d6691933682f0516259a31b39d2cebcedec0a5
- https://git.kernel.org/stable/c/4c38600feb81c670edb82e49d201d3d2d00cd4c3
- https://git.kernel.org/stable/c/8e3a3192ef78d8302916408d62813b1fddfc8972
- https://git.kernel.org/stable/c/a09dc10d1353f0e92c21eae2a79af1c2b1ddcde8
- https://git.kernel.org/stable/c/cf29329a13df79c198b45dfc92577638d30b56fa
- https://git.kernel.org/stable/c/f221baa80e5959a0c08a7e34abbf2a4d3cf0e1c2