Wind River Support Network

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.
Data source: kernel.org (416baaa9-dc9f-4396-8d5f-8c081fb06d67)