CVE Catalog

CVE-2026-90103

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Elevated risk
0.69%

51th percentile - higher than 51% of all known CVEs

Summary

In the Linux kernel, the NFSv4.2 implementation has a LAYOUTSTATS send buffer exhaustion issue. The encode_layoutstats_maxsz macro budgets 256 bytes, but the flexfiles record can exceed that because the server controls the filehandle and address lengths. This can drive the encoder past the end of the send buffer and leave a mutex permanently held when xdr_reserve_space() returns NULL.

Risk Assessment

A buffer overrun and permanently held mutex may occur, leading to system hang or crash.

Recommendation

Update the Linux kernel to a version containing the fix that raises PNFS_LAYOUTSTATS_MAXSIZE to 384.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: fix LAYOUTSTATS send buffer exhaustion encode_layoutstats_maxsz budgets XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE), i.e. 256 bytes, for the layoutupdate4 body written by the layout driver. The flexfiles record can exceed that. ff_layout_encode_ff_layoutupdate() emits, per data server, a netaddr4, an nfs_fh4, two ff_io_latency4, an nfstime4 and a bool. A data server whose filehandle is NFS_MAXFHSIZE bytes long already accounts for 132 of those bytes, and the two ff_io_latency4 at 64 bytes each, the nfstime4 and the bool add a further 144, so the body passes 256 bytes before the netaddr4 is encoded at all. encode_layoutstats() additionally writes the deviceid4 and the layoutupdate4 lou_type word, neither of which the macro accounts for. The filehandle and the address are both chosen by the server, through LAYOUTGET and GETDEVICEINFO, so it can drive the encoder past the end of the send buffer. xdr_reserve_space() returns NULL once that happens, and the two ff_layout_encode_io_latency() calls run with dss_info->mirror->lock held, so a NULL return there leaves the lock permanently held. Raise PNFS_LAYOUTSTATS_MAXSIZE to 384 so that the record fits inside the reservation.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS