SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.157, 6.12.109, 6.18.50, 7.2.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The Linux kernel's SUNRPC/RPCSEC_GSS server-side authentication code, which handles Kerberos-based NFS and related RPC services, is affected. Early decode failures could leave a reused credential structure holding stale or dangling pointer data, which could lead to memory corruption or a crash in the kernel.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry svcauth_gss_decode_credbody() writes the caller's rpc_gss_wire_cred field by field and assigns gc_ctx.len only on the success tail. The caller storage is svcdata->clcred, which lives in the per-svc_rqst gss_svc_data and is reused across requests. Early decode failures leave partially decoded state mixed with residue from the prior request. The trailing body_len tightness check is the sharpest case: xdr_stream_decode_opaque_inline() has already written gc_ctx.data with a borrowed inline pointer into the current request's XDR pages, but gc_ctx.len retains its prior value. Once the request pages are released the pooled clcred carries a dangling pointer paired with a stale length. Zero the caller's rpc_gss_wire_cred at function entry so that every early-return path leaves a deterministic all-zero cred. On the trailing tightness-check path, gc_ctx.len is now zero instead of stale, which neuters length-driven consumers such as gss_svc_searchbyctx() that would otherwise walk the dangling data pointer.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From b0bc53470d1af01f62a0fe2d405cf56477804863 · fixed in 56b29d62017c7dd1718d060dd5b3a2ce61095d0c; From b0bc53470d1af01f62a0fe2d405cf56477804863 · fixed in 0e18641708eaa8bc3c1ff338cd844aeadbd52bac; From b0bc53470d1af01f62a0fe2d405cf56477804863 · fixed in e0778464049b0238f2915a40007a4154f86cf351; From b0bc53470d1af01f62a0fe2d405cf56477804863 · fixed in 0fa8a8acae57e6373962741d5b06d13f44aba6a9; From b0bc53470d1af01f62a0fe2d405cf56477804863 · fixed in 11539e8fcce0b0af062ae5fecf7b3676c2f7aeed
- Linux Linux
6.3
- KernelLinux
From 6.3.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.2.4