{"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":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","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":"2026-09-25","sourceUpdated":"2026-09-25T05:17:00.567","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"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93228.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-93228"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2540230"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-93228"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93228"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93228.mbox"},{"url":"https://access.redhat.com/errata/RHSA-2026:83207"},{"url":"https://access.redhat.com/errata/RHSA-2026:83156"},{"url":"https://access.redhat.com/errata/RHSA-2026:83157"},{"url":"https://access.redhat.com/errata/RHSA-2026:83159"},{"url":"https://git.kernel.org/stable/c/28c5a3a572f6cf81ac304459cfd515480995d62a"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"ingestedAt":"2026-09-24T15:45:56.662Z","epss":0.00467,"epssPercentile":0.40247,"cwe":["CWE-839"],"scores":{"nvd":9.1,"vendor":5.5,"cna":9.1},"patched":["10base_smtv","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_crb_v_8","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_hidden_v_10","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_nfv_v_8","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_10","enterprise_linux_rt_v_8","enterprise_linux_real_time_v_9"],"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.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93228.json)\n- **RHSA-2026:83207** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:83207)\n- **RHSA-2026:83156** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83156)\n- **RHSA-2026:83157** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83157)\n- **RHSA-2026:83159** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:83159)","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":210513,"id":"CVE-2026-93228","ts":1790316054483,"field":"cvss","old":null,"new":"9.1"},{"seq":210512,"id":"CVE-2026-93228","ts":1790316054483,"field":"severity","old":"none","new":"critical"}]}