CVE-2026-93207

/// Technical 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.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References