{"cve":"CVE-2026-93228","nvd":{"published":"2026-09-24T16:17:18.253","modified":"2026-10-21T13:21:05.080","status":"Received","description":"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 > 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1},"cwes":[],"references":["https://git.kernel.org/stable/c/28c5a3a572f6cf81ac304459cfd515480995d62a","https://git.kernel.org/stable/c/45dbdb2637b7fc5f1355b588780d2a7fb0516805","https://git.kernel.org/stable/c/9808eb7656666acc7291bae9ab6b987bd16e47e0","https://git.kernel.org/stable/c/a798714b58041e88716db3bf8fb03ae13eecd54a","https://git.kernel.org/stable/c/fe533ae1bed2ef2b3d54ee7ab410da1874ed3d4f"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-93228","score":0.00467,"percentile":0.40151,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}