{"apiVersion":"1.0","identifier":"CVE-2026-72491","description":"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.","publishedAt":"2026-08-15T06:22:23","lastModifiedAt":"2026-08-17T06:19:17","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-72491","cvssScore":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00724,"riskScore":1.04,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-72491","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-72491","en":"https://www.redsauce.net/en/cves/CVE-2026-72491","fr":"https://www.redsauce.net/fr/cves/CVE-2026-72491","pt":"https://www.redsauce.net/pt/cves/CVE-2026-72491","de":"https://www.redsauce.net/de/cves/CVE-2026-72491","sk":"https://www.redsauce.net/sk/cves/CVE-2026-72491","el":"https://www.redsauce.net/el/cves/CVE-2026-72491"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-72491"}}