{"id":"CVE-2026-72491","revision":"459290c1bb1f48c8ba1ccbc4ecebfcb0","records":[{"revision":"459290c1bb1f48c8ba1ccbc4ecebfcb0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72491","aliases":[],"title":"net/9p: fix race condition on rdma->state in trans_rdma.c","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/9p: fix race condition on rdma->state in trans_rdma.c\n\nThe rdma->state field is modified without holding req_lock in both\nrecv_done() and p9_cm_event_handler(), while rdma_request() accesses\nthe same field under the req_lock spinlock. This inconsistent locking\ncreates a race condition:\n\n- recv_done() running in softirq completion context sets\n  rdma->state = P9_RDMA_FLUSHING without acquiring req_lock\n\n- p9_cm_event_handler() modifies rdma->state at multiple points\n  (ADDR_RESOLVED, ROUTE_RESOLVED, ESTABLISHED, CLOSED) without\n  req_lock\n\n- rdma_request() uses spin_lock_irqsave(&rdma->req_lock, flags) to\n  protect the read-modify-write of rdma->state\n\nThe race can cause lost state transitions: recv_done() or the CM\nevent handler could set state to FLUSHING/CLOSED while rdma_request()\nis concurrently checking or modifying state under the lock, leading to\nthe FLUSHING transition being silently overwritten by CLOSING. This\ncorrupts the connection state machine and can cause use-after-free on\nRDMA request objects during teardown.\n\nFix by adding req_lock protection to all rdma->state modifications in\nrecv_done() and p9_cm_event_handler(), matching the pattern already\nused in rdma_request(). Use spin_lock_irqsave/spin_unlock_irqrestore\nin the CM event handler since it can race with recv_done() which runs\nin softirq context.\n\nTested with a kernel module that races two threads (simulating\nrdma_request and recv_done/CM handler) on rdma->state with proper\nlocking: 5.5M+ FLUSHING writes over 27M iterations with 0 lost\ntransitions.","state":0,"publishedAt":"2026-08-15T05:57:26.281+00:00","modifiedAt":"2026-10-16T18:55:26.515+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/9p/trans_rdma.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"4cee2b8766045059d5e0b8114837b4a8efe827ac\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"5424138848eb7d7d8a7196676e90a2cbf2142454\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"3970a19a80de530b801b6256354d4a529a9a2d6c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"151f8cf5b23d8a534d884432a82a6d54d5a61989\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"13bf9879b778b2f4b260b45bed18f31806120d1e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"ebbcbe5c0db215feecc17def06178da443f4eea6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"473c7dd1d7b59ff8f88a5154737e3eac78a96e5b\",\n                            \"lessThan\": \"7d54894a1ee265a72d70f7cae1da6cc774cccc71\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c01ddaa54d7411e964ffd250c018d8469c5852f2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9e69c673fe077b8dc491cd8406c9bdcb1f76dee2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e48e7e27e4dfd00c81e0381e7cee610cce021452\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4.4.185\",\n                            \"lessThan\": \"4.5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.9.185\",\n                            \"lessThan\": \"4.10\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.14.132\",\n                            \"lessThan\": \"4.15\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.19.57\",\n                            \"lessThan\": \"4.20\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/9p/trans_rdma.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.20\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.20\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://git.kernel.org/stable/c/4cee2b8766045059d5e0b8114837b4a8efe827ac","https://git.kernel.org/stable/c/5424138848eb7d7d8a7196676e90a2cbf2142454","https://git.kernel.org/stable/c/3970a19a80de530b801b6256354d4a529a9a2d6c","https://git.kernel.org/stable/c/8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b","https://git.kernel.org/stable/c/151f8cf5b23d8a534d884432a82a6d54d5a61989","https://git.kernel.org/stable/c/13bf9879b778b2f4b260b45bed18f31806120d1e","https://git.kernel.org/stable/c/ebbcbe5c0db215feecc17def06178da443f4eea6","https://git.kernel.org/stable/c/7d54894a1ee265a72d70f7cae1da6cc774cccc71"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72491","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72491","identifiers":["CVE-2026-72491"]},"retained":false,"historicalAffected":[]}],"coverage":[]}