{"id":"CVE-2026-74666","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74666","summary":"packet: synchronize pressure clearing with ring reconfiguration","details":"In the Linux kernel, the following vulnerability has been resolved:\n\npacket: synchronize pressure clearing with ring reconfiguration\n\npacket_set_ring() updates the RX ring state under sk_receive_queue.lock,\nbut used to publish the tpacket receive mode through po->prot_hook.func\nafter releasing that lock. packet_poll() and packet_recvmsg() can then\nrun the pressure clearing path after the ring has been cleared while\nstill seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference\nstale or NULL ring storage.\n\nMove the existing receive hook assignment into the same\nsk_receive_queue.lock section as the ring state update. Keep the\nassignment otherwise unchanged, including on TX ring reconfiguration, to\navoid adding behavior changes that are not required for the fix.\n\nSerialize packet_recvmsg() pressure clearing with the same queue lock\nonly after PACKET_SOCK_PRESSURE has been observed. If the flag is clear\nand the socket has moved away from tpacket_rcv, packet_set_ring() has\nalready detached the socket and waited for synchronize_net(), so no new\npacket input can set the flag again.\n\npacket_poll() already holds sk_receive_queue.lock, so it uses the new\nunlocked helper directly.","published":"2026-08-22T15:32:38.098Z","modified":"2026-08-24T11:47:18.949078926Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.6.152"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1a35da325cac4d5bcad76a2aa943408a6f1d9000"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2c7b5eb87b2b288cdbde825f21d2b83b2f5da747"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a08196c3cc105947746ec21309edfbb60275fcdb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ad740b4990347521f0db260d381f9f74e7b340ba"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cf8189b82bb93f219ab740e0346c919ad65ada62"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74666.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74666"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-24T11:47:18.949078926Z"}}