{"id":"AZL-100851","summary":"CVE-2026-89530 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Reject inline replies that overflow the pull-up buffer\n\nAn RPC-over-RDMA client can request a reply, such as an NFS READ\npayload, without providing a Write list or a Reply chunk to carry\nit. When such a reply needs more scatter/gather entries than the\ndevice's Send Queue supports, svc_rdma_pull_up_needed() selects\npull-up and svc_rdma_pull_up_reply_msg() linearizes the whole\nreply into sctxt-\u003esc_xprt_buf. That buffer is only sc_max_req_size\nbytes, while the reply on this path is bounded only by the client's\nrequest, so svc_rdma_xb_linearize() copies past the end of the\nbuffer and corrupts adjacent slab memory. The oversized length is\nthen stored in sc_sges[0].length and posted, so the device also\nreads beyond the mapped region.\n\nThe SGE-exhaustion branch is the only pull-up path that can exceed\nthe buffer: the threshold branch pulls up only replies smaller\nthan RPCRDMA_PULLUP_THRESH, and replies that fit the device's SGE\nbudget are sent directly without linearization. Make\nsvc_rdma_pull_up_needed() report -E2BIG when the reply it would\npull up cannot fit sc_max_req_size, and fail the request with\nERR_CHUNK as RFC 8166 Section 4.5.3 directs rather than dropping\nthe connection.\n\nThe helper no longer answers a simple yes/no question: it now\nreports pull-up, no pull-up, or -E2BIG for a reply too large to\nlinearize. Rename svc_rdma_pull_up_needed() to\nsvc_rdma_check_pull_up() so its name no longer implies a boolean\npredicate.","modified":"2026-09-13T06:06:36Z","published":"2026-09-11T20:19:35Z","upstream":["CVE-2026-89530"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89530"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100851.json"}}],"schema_version":"1.9.0"}