{"id":"CVE-2026-93228","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject Write/Reply chunks with segcount 0\n\nA peer can send a Write or Reply chunk whose segcount field is zero.\nxdr_check_write_chunk() only rejects segcount >…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject Write/Reply chunks with segcount 0\n\nA peer can send a Write or Reply chunk whose segcount field is zero.\nxdr_check_write_chunk() only rejects segcount >…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 < fe533ae1bed2ef2b3d54ee7ab410da1874ed3d4f","Linux >= 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 < a798714b58041e88716db3bf8fb03ae13eecd54a","Linux >= 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 < 45dbdb2637b7fc5f1355b588780d2a7fb0516805","Linux >= 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 < 9808eb7656666acc7291bae9ab6b987bd16e47e0","Linux 5.11"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T16:17:18.253","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93228","references":[{"url":"https://git.kernel.org/stable/c/45dbdb2637b7fc5f1355b588780d2a7fb0516805","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9808eb7656666acc7291bae9ab6b987bd16e47e0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a798714b58041e88716db3bf8fb03ae13eecd54a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fe533ae1bed2ef2b3d54ee7ab410da1874ed3d4f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-24T15:45:56.662Z","slug":"CVE-2026-93228","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject Write/Reply chunks with segcount 0\n\nA peer can send a Write or Reply chunk whose segcount field is zero.\nxdr_check_write_chunk() only rejects segcount > rc_maxpages, so zero\npasses the range check, and xdr_inline_decode(stream, 0) returns the\ncurrent (non-NULL) cursor without advancing. The function returns\ntrue and pcl_alloc_write() then links a struct svc_rdma_chunk with\nch_segcount == 0 onto rc_write_pcl or rc_reply_pcl.\n\nAn earlier patch in this series made pcl_for_each_segment() safe for\nch_segcount == 0, so this no longer drives the memory walk it used\nto. Rejecting the malformed frame at the decode boundary is still\nworthwhile as defense in depth: it keeps degenerate zero-segment\nchunks off the parsed chunk lists entirely, so any future consumer\nthat walks ch_segments directly cannot observe one, and it makes the\nzero-floor easy to backport to trees where the macro change is more\nintrusive. RFC 8166 has no meaning for a Write/Reply chunk that\ndescribes no remote buffer, so no legitimate client is affected.\n\nxdr_check_reply_chunk() funnels Reply chunks through\nxdr_check_write_chunk() and inherits the same rejection.\n\npcl_alloc_write() also links each chunk onto the parsed chunk list\nbefore filling its segment array. If a future change weakens the\nsegcount-0 rejection, an incomplete chunk is visible to consumers\nduring the fill loop. Reorder so that list_add_tail() follows the\nsegment fill loop, ensuring only fully-populated chunks appear on\nthe list.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}