CVE-2026-93228EPSS p38.7%
CVE-2026-93228CVE-2026-93228
Description
In the Linux kernel, the following vulnerability has been resolved:
svcrdma: Reject Write/Reply chunks with segcount 0
A peer can send a Write or Reply chunk whose segcount field is zero.
xdr_check_write_chunk() only rejects segcount > rc_maxpages, so zero
passes the range check, and xdr_inline_decode(stream, 0) returns the
current (non-NULL) cursor without advancing. The function returns
true and pcl_alloc_write() then links a struct svc_rdma_chunk with
ch_segcount == 0 onto rc_write_pcl or rc_reply_pcl.
An earlier patch in this series made pcl_for_each_segment() safe for
ch_segcount == 0, so this no longer drives the memory walk it used
to. Rejecting the malformed frame at the decode boundary is still
worthwhile as defense in depth: it keeps degenerate zero-segment
chunks off the parsed chunk lists entirely, so any future consumer
that walks ch_segments directly cannot observe one, and it makes the
zero-floor easy to backport to trees where the macro change is more
intrusive. RFC
Scoring
| CVSS | 9.1 () |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
| EPSS | 0.47% probability of exploitation · percentile 38.7% · 2026-10-05T12:00:23Z |
| Last modified | 2026-09-25 |