SB20260720157 - Race condition in Linux kernel netfs

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-64065)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper state management in netfs_write_begin() when handling write operations through the netfs and ceph write path. A local user can trigger the kernel BUG with crafted write activity to cause a denial of service.

The issue manifests as a VM_BUG_ON_FOLIO condition that can lead to an invalid opcode exception and kernel crash.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/51ffb788f074c0a61953086f49008028c1e7b645
• https://git.kernel.org/stable/c/5ad05b6f5df296ef046589f222bb2587495b991e
• https://git.kernel.org/stable/c/b63971238beb79cf701dac33c6cefc56c07c89fa
• https://git.kernel.org/stable/c/dc7832d05deb4d632e8035e3299e31a3528fa0d0