{"id":"CVE-2026-72464","summary":"xprtrdma: Repost Receive buffers for malformed replies","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxprtrdma: Repost Receive buffers for malformed replies\n\nrpcrdma_wc_receive() decrements the transport's Receive count for\nevery completion before it dispatches a successful Receive to\nrpcrdma_reply_handler(). The handler must post a replacement\nReceive WR before returning unless ownership of the rep has moved\nelsewhere, as on the backchannel path.\n\nCommit 2ae50ad68cd7 (\"xprtrdma: Close window between waking RPC\nsenders and posting Receives\") moved the Receive refill out of\nrpcrdma_wc_receive(), where it had run ahead of every reply, into\nrpcrdma_reply_handler() so that the responder's credit grant could\nbe parsed before reposting. The bad-version and short-reply exits\nnever reach that refill: they recycle the rep and return without\ncalling rpcrdma_post_recvs().\n\nA remote peer can therefore drain the client's posted Receive\nqueue by sending a sustained stream of replies that are shorter\nthan the fixed transport header or that carry an unrecognized\nRPC/RDMA version. Each such reply consumes one posted Receive\nwithout replacing it. Once the queue empties, the peer's next\nSend finds no posted Receive and the transport stalls until\nreconnect.\n\nRoute both malformed-reply exits through the shared repost tail\nafter recycling the rep, refilling against buf-\u003erb_credits, the\nmost recent accepted credit grant. Neither exit updates the\ncongestion window, so RPCs admitted under the previous grant\nremain in flight awaiting replies. A smaller refill target would\nlet a stream of malformed replies ratchet the posted Receive count\ndown to the batch floor while the congestion window still admits\nrb_credits RPCs; a burst of valid replies to those RPCs could then\noverrun the posted Receives, and because the client connects with\nrnr_retry_count of zero, a single RNR NAK terminates the\nconnection. Refilling against rb_credits also restores the target\nthat applied to malformed replies before commit 2ae50ad68cd7\n(\"xprtrdma: Close window between waking RPC senders and posting\nReceives\") when rpcrdma_post_recvs() computed it from rb_credits\ninternally. rb_credits is at least one from connection\nestablishment onward, so the repost path always keeps Receives\nposted.","modified":"2026-10-17T10:30:15.616822263Z","published":"2026-08-15T05:57:08.080Z","related":["SUSE-SU-2026:23477-1","SUSE-SU-2026:23481-1","SUSE-SU-2026:23528-1","SUSE-SU-2026:23529-1","SUSE-SU-2026:23881-1","SUSE-SU-2026:23887-1","SUSE-SU-2026:23897-1","SUSE-SU-2026:23902-1","SUSE-SU-2026:4120-1","SUSE-SU-2026:4254-1","openSUSE-SU-2026:21910-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72464.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/007b4da2f38dcc16a13265416f4ca9f179bab610"},{"type":"WEB","url":"https://git.kernel.org/stable/c/19fae02b272ee4bcdfb5db57f402d28f1697167a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4322fd9645ee769ad29ce5caea74a1cd9b17269d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/abc011ddaf1617e3e82d8a1e87daa7ddbfb9bac5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d7c531ab477ae94fd03771d707fd29c787408039"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ef6fb8a5c521f1a07f85202d13e8f2898f247362"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72464.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72464"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2ae50ad68cd79224198b525f7bd645c9da98b6ff"},{"fixed":"ef6fb8a5c521f1a07f85202d13e8f2898f247362"},{"fixed":"4322fd9645ee769ad29ce5caea74a1cd9b17269d"},{"fixed":"19fae02b272ee4bcdfb5db57f402d28f1697167a"},{"fixed":"007b4da2f38dcc16a13265416f4ca9f179bab610"},{"fixed":"d7c531ab477ae94fd03771d707fd29c787408039"},{"fixed":"abc011ddaf1617e3e82d8a1e87daa7ddbfb9bac5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.4.13"},{"fixed":"5.5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3791c5982ba1eebf2900ee7ca7b9a89619c26d54"}]}],"versions":["v5.4.302","v5.4.301","v5.4.300","v5.4.299","v5.4.298","v5.4.297","v5.4.296","v5.4.295","v5.4.294","v5.4.293","v5.4.292","v5.4.291","v5.4.290","v5.4.289","v5.4.288","v5.4.287","v5.4.286","v5.4.285","v5.4.284","v5.4.283","v5.4.282","v5.4.281","v5.4.280","v5.4.279","v5.4.278","v5.4.277","v5.4.276","v5.4.275","v5.4.274","v5.4.273","v5.4.272","v5.4.271","v5.4.270","v5.4.269","v5.4.268","v5.4.267","v5.4.266","v5.4.265","v5.4.264","v5.4.263","v5.4.262","v5.4.261","v5.4.260","v5.4.259","v5.4.258","v5.4.257","v5.4.256","v5.4.255","v5.4.254","v5.4.253","v5.4.252","v5.4.251","v5.4.250","v5.4.249","v5.4.248","v5.4.247","v5.4.246","v5.4.245","v5.4.244","v5.4.243","v5.4.242","v5.4.241","v5.4.240","v5.4.239","v5.4.238","v5.4.237","v5.4.236","v5.4.235","v5.4.234","v5.4.233","v5.4.232","v5.4.231","v5.4.230","v5.4.229","v5.4.228","v5.4.227","v5.4.226","v5.4.225","v5.4.224","v5.4.223","v5.4.222","v5.4.221","v5.4.220","v5.4.219","v5.4.218","v5.4.217","v5.4.216","v5.4.215","v5.4.214","v5.4.213","v5.4.212","v5.4.211","v5.4.210","v5.4.209","v5.4.208","v5.4.207","v5.4.206","v5.4.205","v5.4.204","v5.4.203","v5.4.202","v5.4.201","v5.4.200","v5.4.199","v5.4.198","v5.4.197","v5.4.196","v5.4.195","v5.4.194","v5.4.193","v5.4.192","v5.4.191","v5.4.190","v5.4.189","v5.4.188","v5.4.187","v5.4.186","v5.4.185","v5.4.184","v5.4.183","v5.4.182","v5.4.181","v5.4.180","v5.4.179","v5.4.178","v5.4.177","v5.4.176","v5.4.175","v5.4.174","v5.4.173","v5.4.172","v5.4.171","v5.4.170","v5.4.169","v5.4.168","v5.4.167","v5.4.166","v5.4.165","v5.4.164","v5.4.163","v5.4.162","v5.4.161","v5.4.160","v5.4.159","v5.4.158","v5.4.157","v5.4.156","v5.4.155","v5.4.154","v5.4.153","v5.4.152","v5.4.151","v5.4.150","v5.4.149","v5.4.148","v5.4.147","v5.4.146","v5.4.145","v5.4.144","v5.4.143","v5.4.142","v5.4.141","v5.4.140","v5.4.139","v5.4.138","v5.4.137","v5.4.136","v5.4.135","v5.4.134","v5.4.133","v5.4.132","v5.4.131","v5.4.130","v5.4.129","v5.4.128","v5.4.127","v5.4.126","v5.4.125","v5.4.124","v5.4.123","v5.4.122","v5.4.121","v5.4.120","v5.4.119","v5.4.118","v5.4.117","v5.4.116","v5.4.115","v5.4.114","v5.4.113","v5.4.112","v5.4.111","v5.4.110","v5.4.109","v5.4.108","v5.4.107","v5.4.106","v5.4.105","v5.4.104","v5.4.103","v5.4.102","v5.4.101","v5.4.100","v5.4.99","v5.4.98","v5.4.97","v5.4.96","v5.4.95","v5.4.94","v5.4.93","v5.4.92","v5.4.91","v5.4.90","v5.4.89","v5.4.88","v5.4.87","v5.4.86","v5.4.85","v5.4.84","v5.4.83","v5.4.82","v5.4.81","v5.4.80","v5.4.79","v5.4.78","v5.4.77","v5.4.76","v5.4.75","v5.4.74","v5.4.73","v5.4.72","v5.4.71","v5.4.70","v5.4.69","v5.4.68","v5.4.67","v5.4.66","v5.4.65","v5.4.64","v5.4.63","v5.4.62","v5.4.61","v5.4.60","v5.4.59","v5.4.58","v5.4.57","v5.4.56","v5.4.55","v5.4.54","v5.4.53","v5.4.52","v5.4.51","v5.4.50","v5.4.49","v5.4.48","v5.4.47","v5.4.46","v5.4.45","v5.4.44","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