{"id":"CVE-2026-99166","state":"PUBLISHED","title":"net: rds: fix uninitialized trans dereference in CM event handler","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: rds: fix uninitialized trans dereference in CM event handler\n\nrds_rdma_cm_event_handler_cmn() assigns trans only when the RDMA\ndevice is an InfiniBand CA (RDMA_NODE_IB_CA).  On any other device\ntype, e.g. an iWARP RNIC such as siw, trans stays uninitialized, but\nthe event switch dereferences it: unconditionally in the\nRDMA_CM_EVENT_CONNECT_REQUEST case via trans->cm_handle_connect(),\nand (with a connection context) in the ROUTE_RESOLVED and\nESTABLISHED cases.\n\nAn RDS listener on an iWARP device therefore crashes the kernel as\nsoon as a connect request arrives: with CONFIG_INIT_STACK_ALL_ZERO\nthe wild load becomes a NULL dereference at offset 0xa0\n(&trans->cm_handle_connect) in the iw_cm_wq workqueue.\n\nGCC masks the bug in default builds by folding the uninitialized\nload into &rds_ib_transport; Clang-built kernels take the real\nuninitialized path and oops.\n\nThe active side can land on a non-IB device too: the id that\nrds_ib_conn_path_connect() creates is not restricted to a node type,\nso rdma_resolve_addr() binds it to whichever device serves the local\naddress, and an iWARP RNIC on the same netdev qualifies.  The crash\nthere is different: resolving a route on an iWARP id never fills in\ncm_id->route.path_rec, and the ROUTE_RESOLVED case writes\npath_rec[0].sl before it calls into the transport.\n\nThe iWARP transport was dropped long ago and IB is the only\ntransport left, so make that explicit: initialize trans to\n&rds_ib_transport at declaration, drop the conditional assignment,\nreject a connect request that arrives on a non-IB device, and drop a\nconnection whose address resolved to one instead of resolving a\nroute on it.  The rejection is limited to RDMA_CM_EVENT_CONNECT_REQUEST\non purpose: a non-zero return from the handler makes rdma_cm destroy\nthe id the event was delivered on, which is right for the request's\nfreshly created id but would free a connection id that RDS still owns\nfor any other event.  On the active side the id stays ic->i_cm_id and\nthe connection's shutdown destroys it, so that case returns 0.\n\n[achender: reject only on RDMA_CM_EVENT_CONNECT_REQUEST instead of\n bailing out for every event on a non-IB device, so that rdma_cm does\n not destroy connection ids RDS still tracks; drop a connection whose\n address resolved to a non-IB device before a route is resolved on it;\n changelog adjusted]","publishedAt":"2026-10-28T10:35:18.050Z","updatedAt":"2026-10-30T12:42:32.571Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"0d15e853aa88da5375edd32b39d08a048b64a1c5","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"8c77774535c3d6162929521a6fa11e3db086fa32","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"8973f70cb068012d83cff1cfa3f45ef94ab02267","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"a2fde862b98db8908e2ebaffbb35a75a0e9d5b33","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"074bb7cdc3e26afa698888ba56fc1df0e3f24650","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"5f23e4e3a31dacfd82a8f56be253adc0910ee84f","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"ca14c289ed9ffed6cc64290d039e923e5720a8bf","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/rdma_transport.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/rdma_transport.c"]}],"references":["https://git.kernel.org/stable/c/0d15e853aa88da5375edd32b39d08a048b64a1c5","https://git.kernel.org/stable/c/8c77774535c3d6162929521a6fa11e3db086fa32","https://git.kernel.org/stable/c/8973f70cb068012d83cff1cfa3f45ef94ab02267","https://git.kernel.org/stable/c/a2fde862b98db8908e2ebaffbb35a75a0e9d5b33","https://git.kernel.org/stable/c/074bb7cdc3e26afa698888ba56fc1df0e3f24650","https://git.kernel.org/stable/c/5f23e4e3a31dacfd82a8f56be253adc0910ee84f","https://git.kernel.org/stable/c/ca14c289ed9ffed6cc64290d039e923e5720a8bf","https://git.kernel.org/stable/c/492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8"],"weaknesses":[],"ingestedAt":"2026-10-30T13:02:04.640Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99166.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99166","state":"PUBLISHED","datePublished":"2026-10-28T10:35:18.050Z","dateUpdated":"2026-10-30T12:42:32.571Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.398Z"},"containers":{"cna":{"title":"net: rds: fix uninitialized trans dereference in CM event handler","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: rds: fix uninitialized trans dereference in CM event handler\n\nrds_rdma_cm_event_handler_cmn() assigns trans only when the RDMA\ndevice is an InfiniBand CA (RDMA_NODE_IB_CA).  On any other device\ntype, e.g. an iWARP RNIC such as siw, trans stays uninitialized, but\nthe event switch dereferences it: unconditionally in the\nRDMA_CM_EVENT_CONNECT_REQUEST case via trans->cm_handle_connect(),\nand (with a connection context) in the ROUTE_RESOLVED and\nESTABLISHED cases.\n\nAn RDS listener on an iWARP device therefore crashes the kernel as\nsoon as a connect request arrives: with CONFIG_INIT_STACK_ALL_ZERO\nthe wild load becomes a NULL dereference at offset 0xa0\n(&trans->cm_handle_connect) in the iw_cm_wq workqueue.\n\nGCC masks the bug in default builds by folding the uninitialized\nload into &rds_ib_transport; Clang-built kernels take the real\nuninitialized path and oops.\n\nThe active side can land on a non-IB device too: the id that\nrds_ib_conn_path_connect() creates is not restricted to a node type,\nso rdma_resolve_addr() binds it to whichever device serves the local\naddress, and an iWARP RNIC on the same netdev qualifies.  The crash\nthere is different: resolving a route on an iWARP id never fills in\ncm_id->route.path_rec, and the ROUTE_RESOLVED case writes\npath_rec[0].sl before it calls into the transport.\n\nThe iWARP transport was dropped long ago and IB is the only\ntransport left, so make that explicit: initialize trans to\n&rds_ib_transport at declaration, drop the conditional assignment,\nreject a connect request that arrives on a non-IB device, and drop a\nconnection whose address resolved to one instead of resolving a\nroute on it.  The rejection is limited to RDMA_CM_EVENT_CONNECT_REQUEST\non purpose: a non-zero return from the handler makes rdma_cm destroy\nthe id the event was delivered on, which is right for the request's\nfreshly created id but would free a connection id that RDS still owns\nfor any other event.  On the active side the id stays ic->i_cm_id and\nthe connection's shutdown destroys it, so that case returns 0.\n\n[achender: reject only on RDMA_CM_EVENT_CONNECT_REQUEST instead of\n bailing out for every event on a non-IB device, so that rdma_cm does\n not destroy connection ids RDS still tracks; drop a connection whose\n address resolved to a non-IB device before a route is resolved on it;\n changelog adjusted]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"0d15e853aa88da5375edd32b39d08a048b64a1c5","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"8c77774535c3d6162929521a6fa11e3db086fa32","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"8973f70cb068012d83cff1cfa3f45ef94ab02267","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"a2fde862b98db8908e2ebaffbb35a75a0e9d5b33","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"074bb7cdc3e26afa698888ba56fc1df0e3f24650","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"5f23e4e3a31dacfd82a8f56be253adc0910ee84f","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"ca14c289ed9ffed6cc64290d039e923e5720a8bf","versionType":"git"},{"version":"dcdede0406d30e14a6ed727dce69dfac0518371d","status":"affected","lessThan":"492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/rdma_transport.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/rdma_transport.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0d15e853aa88da5375edd32b39d08a048b64a1c5"},{"url":"https://git.kernel.org/stable/c/8c77774535c3d6162929521a6fa11e3db086fa32"},{"url":"https://git.kernel.org/stable/c/8973f70cb068012d83cff1cfa3f45ef94ab02267"},{"url":"https://git.kernel.org/stable/c/a2fde862b98db8908e2ebaffbb35a75a0e9d5b33"},{"url":"https://git.kernel.org/stable/c/074bb7cdc3e26afa698888ba56fc1df0e3f24650"},{"url":"https://git.kernel.org/stable/c/5f23e4e3a31dacfd82a8f56be253adc0910ee84f"},{"url":"https://git.kernel.org/stable/c/ca14c289ed9ffed6cc64290d039e923e5720a8bf"},{"url":"https://git.kernel.org/stable/c/492ba6ac1b1ffb8a06ff52db0825c1af2cdb28c8"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:42:32.571Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}