CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's NFS server, specifically in the handling of deferred writeback errors during write operations. Due to a failure to reset the write verifier when errors occur, clients may mistakenly believe their unstable write data is durable, leading to potential data loss. Organizations using Linux-based systems with NFS should prioritize addressing this issue to ensure data integrity and compliance with durability contracts.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: reset write verifier on deferred writeback errors nfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to detect deferred writeback errors, but neither rotates the server's write verifier (nn->writeverf) when this check fails. Every other durable-storage-failure path in these functions calls commit_reset_write_verifier() before returning an error. The missing rotation means clients holding UNSTABLE write data under the current verifier will COMMIT, receive the unchanged verifier back, and conclude their data is durable — silently dropping data that failed writeback. This violates the UNSTABLE+COMMIT durability contract (RFC 1813 §3.3.7, RFC 8881 §18.32). Add commit_reset_write_verifier() calls at both filemap_check_wb_err() error sites, matching the pattern used by adjacent error paths in the same functions. The helper already filters -EAGAIN and -ESTALE internally, so the calls are unconditionally safe.
Related CVEs
Other vulnerabilities affecting the same vendor(s)