{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72491", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.936Z", "datePublished": "2026-08-15T05:57:26.281Z", "dateUpdated": "2026-08-17T05:44:52.224Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:44:52.224Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The 9p RDMA client processes RDMA receive completions and CM disconnect events from the remote peer in recv_done() and p9_cm_event_handler(); a malicious or compromised 9p server over RoCE/iWARP can trigger err_out and concurrent teardown without local access.\nAC:L - The attacker controls both sides of the race by sending malformed 9p RDMA replies to drive recv_done() into err_out while forcing disconnects and concurrent rdma_request() error paths; no uncontrollable memory layout or rare victim state is required.\nPR:N - A remote malicious 9p RDMA server needs no credentials on the victim kernel; HPC clusters and virtio-9p backends with persistent trans=rdma mounts let the server alone time malformed replies against in-flight client requests.\nUI:N - No per-attack victim action is needed on existing 9p RDMA mounts—automated workloads, parallel I/O, and server-initiated RDMA disconnects concurrently reach recv_done() and rdma_request() during normal filesystem operation.\nS:U - Impact is kernel heap corruption and local privilege escalation within the victim kernel security domain; UAF on p9_req_t during RDMA teardown does not cross VM, container, or IOMMU isolation boundaries.\nC:H - Lost FLUSHING state transitions corrupt the connection teardown state machine and cause use-after-free on RDMA request (p9_req_t) objects; UAF provides attacker-influenced freed-heap contents usable for arbitrary kernel memory disclosure.\nI:H - Corrupted rdma->state frees in-flight p9_req_t structures while send_done() and p9_client_cb() still hold references, enabling heap grooming and arbitrary kernel write or control-flow hijack primitives.\nA:H - Use-after-free during RDMA request teardown causes kernel oops or panic when dangling p9_req_t objects are accessed, and state-machine corruption alone can hang or crash the 9p RDMA transport." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/9p/trans_rdma.c" ], "versions": [ { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "4cee2b8766045059d5e0b8114837b4a8efe827ac", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "5424138848eb7d7d8a7196676e90a2cbf2142454", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "3970a19a80de530b801b6256354d4a529a9a2d6c", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "151f8cf5b23d8a534d884432a82a6d54d5a61989", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "13bf9879b778b2f4b260b45bed18f31806120d1e", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "ebbcbe5c0db215feecc17def06178da443f4eea6", "status": "affected", "versionType": "git" }, { "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b", "lessThan": "7d54894a1ee265a72d70f7cae1da6cc774cccc71", "status": "affected", "versionType": "git" }, { "version": "3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62", "status": "affected", "versionType": "git" }, { "version": "c01ddaa54d7411e964ffd250c018d8469c5852f2", "status": "affected", "versionType": "git" }, { "version": "9e69c673fe077b8dc491cd8406c9bdcb1f76dee2", "status": "affected", "versionType": "git" }, { "version": "e48e7e27e4dfd00c81e0381e7cee610cce021452", "status": "affected", "versionType": "git" }, { "version": "4.4.185", "lessThan": "4.5", "status": "affected", "versionType": "semver" }, { "version": "4.9.185", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.14.132", "lessThan": "4.15", "status": "affected", "versionType": "semver" }, { "version": "4.19.57", "lessThan": "4.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/9p/trans_rdma.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.185" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.185" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.132" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.57" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4cee2b8766045059d5e0b8114837b4a8efe827ac" }, { "url": "https://git.kernel.org/stable/c/5424138848eb7d7d8a7196676e90a2cbf2142454" }, { "url": "https://git.kernel.org/stable/c/3970a19a80de530b801b6256354d4a529a9a2d6c" }, { "url": "https://git.kernel.org/stable/c/8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b" }, { "url": "https://git.kernel.org/stable/c/151f8cf5b23d8a534d884432a82a6d54d5a61989" }, { "url": "https://git.kernel.org/stable/c/13bf9879b778b2f4b260b45bed18f31806120d1e" }, { "url": "https://git.kernel.org/stable/c/ebbcbe5c0db215feecc17def06178da443f4eea6" }, { "url": "https://git.kernel.org/stable/c/7d54894a1ee265a72d70f7cae1da6cc774cccc71" } ], "title": "net/9p: fix race condition on rdma->state in trans_rdma.c", "x_generator": { "engine": "bippy-1.2.0" } } } }