Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in proc_show_files() When a SMB2 client opens a file with a durable v2 handle and then issues SMB2 SESSION_LOGOFF, session_fd_check() clears fp->tcon = NULL on the reconnectable file pointer but leaves the fp registered in global_ft.idr until the durable scavenger fires (up to fp->durable_timeout seconds later). During that window any read of /proc/fs/ksmbd/files (mode 0400) panics the kernel because proc_show_files() walks global_ft.idr and unconditionally dereferences fp->tcon->id with no NULL guard. Reproducer requires only a successful SMB2 SESSION_SETUP and a share configured with 'durable handles = yes'. KASAN report on mainline 70390501d194: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:proc_show_files+0x118/0x740 Call Trace: proc_show_files+0x118/0x740 seq_read_iter+0x4ef/0xe10 proc_reg_read_iter+0x1b7/0x280 ... Guard the dereference. A durable-disconnected fp legitimately has no tcon; report its tree id as 0 rather than oopsing.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 7.0, < 7.0.11 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/8eab081627b67216d1c8f638b68289b500dc9a6bPatch
- https://git.kernel.org/stable/c/904901561e61a2b559070b20c74a8c95491f30aaPatch
FAQ
What is CVE-2026-64140?
CVE-2026-64140 is a vulnerability with a CVSS score of 7.5 (HIGH). In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix null pointer dereference in proc_show_files() When a SMB2 client opens a file with a durable v2 handle and then issues ...
How severe is CVE-2026-64140?
CVE-2026-64140 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-64140?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.