CVE-2026-72491 (GCVE-0-2026-72491)
Vulnerability from cvelistv5
Published
2026-08-15 05:57
Modified
2026-08-17 05:44
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/9p: fix race condition on rdma->state in trans_rdma.c
The rdma->state field is modified without holding req_lock in both
recv_done() and p9_cm_event_handler(), while rdma_request() accesses
the same field under the req_lock spinlock. This inconsistent locking
creates a race condition:
- recv_done() running in softirq completion context sets
rdma->state = P9_RDMA_FLUSHING without acquiring req_lock
- p9_cm_event_handler() modifies rdma->state at multiple points
(ADDR_RESOLVED, ROUTE_RESOLVED, ESTABLISHED, CLOSED) without
req_lock
- rdma_request() uses spin_lock_irqsave(&rdma->req_lock, flags) to
protect the read-modify-write of rdma->state
The race can cause lost state transitions: recv_done() or the CM
event handler could set state to FLUSHING/CLOSED while rdma_request()
is concurrently checking or modifying state under the lock, leading to
the FLUSHING transition being silently overwritten by CLOSING. This
corrupts the connection state machine and can cause use-after-free on
RDMA request objects during teardown.
Fix by adding req_lock protection to all rdma->state modifications in
recv_done() and p9_cm_event_handler(), matching the pattern already
used in rdma_request(). Use spin_lock_irqsave/spin_unlock_irqrestore
in the CM event handler since it can race with recv_done() which runs
in softirq context.
Tested with a kernel module that races two threads (simulating
rdma_request and recv_done/CM handler) on rdma->state with proper
locking: 5.5M+ FLUSHING writes over 27M iterations with 0 lost
transitions.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 473c7dd1d7b59ff8f88a5154737e3eac78a96e5b Version: 3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62 Version: c01ddaa54d7411e964ffd250c018d8469c5852f2 Version: 9e69c673fe077b8dc491cd8406c9bdcb1f76dee2 Version: e48e7e27e4dfd00c81e0381e7cee610cce021452 Version: 4.4.185 ≤ Version: 4.9.185 ≤ Version: 4.14.132 ≤ Version: 4.19.57 ≤ |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/9p/trans_rdma.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "4cee2b8766045059d5e0b8114837b4a8efe827ac",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "5424138848eb7d7d8a7196676e90a2cbf2142454",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "3970a19a80de530b801b6256354d4a529a9a2d6c",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "151f8cf5b23d8a534d884432a82a6d54d5a61989",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "13bf9879b778b2f4b260b45bed18f31806120d1e",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "ebbcbe5c0db215feecc17def06178da443f4eea6",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"lessThan": "7d54894a1ee265a72d70f7cae1da6cc774cccc71",
"status": "affected",
"version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
"versionType": "git"
},
{
"status": "affected",
"version": "3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62",
"versionType": "git"
},
{
"status": "affected",
"version": "c01ddaa54d7411e964ffd250c018d8469c5852f2",
"versionType": "git"
},
{
"status": "affected",
"version": "9e69c673fe077b8dc491cd8406c9bdcb1f76dee2",
"versionType": "git"
},
{
"status": "affected",
"version": "e48e7e27e4dfd00c81e0381e7cee610cce021452",
"versionType": "git"
},
{
"lessThan": "4.5",
"status": "affected",
"version": "4.4.185",
"versionType": "semver"
},
{
"lessThan": "4.10",
"status": "affected",
"version": "4.9.185",
"versionType": "semver"
},
{
"lessThan": "4.15",
"status": "affected",
"version": "4.14.132",
"versionType": "semver"
},
{
"lessThan": "4.20",
"status": "affected",
"version": "4.19.57",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/9p/trans_rdma.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"lessThan": "4.20",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.261",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.212",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.178",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.145",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.97",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "4.20",
"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",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/9p: fix race condition on rdma-\u003estate in trans_rdma.c\n\nThe rdma-\u003estate 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-\u003estate = P9_RDMA_FLUSHING without acquiring req_lock\n\n- p9_cm_event_handler() modifies rdma-\u003estate at multiple points\n (ADDR_RESOLVED, ROUTE_RESOLVED, ESTABLISHED, CLOSED) without\n req_lock\n\n- rdma_request() uses spin_lock_irqsave(\u0026rdma-\u003ereq_lock, flags) to\n protect the read-modify-write of rdma-\u003estate\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-\u003estate 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-\u003estate with proper\nlocking: 5.5M+ FLUSHING writes over 27M iterations with 0 lost\ntransitions."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"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\u2014automated 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-\u003estate 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."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:44:52.224Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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-\u003estate in trans_rdma.c",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72491",
"datePublished": "2026-08-15T05:57:26.281Z",
"dateReserved": "2026-08-09T03:40:39.936Z",
"dateUpdated": "2026-08-17T05:44:52.224Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…