{"id":"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-\u003eprot_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.","modified":"2026-08-24T11:47:18.949078926Z","published":"2026-08-22T15:32:38.098Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74666.json"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2ccdbaa6d55b0656244ba57c4b56765a0af76c0a"},{"fixed":"cf8189b82bb93f219ab740e0346c919ad65ada62"},{"fixed":"ad740b4990347521f0db260d381f9f74e7b340ba"},{"fixed":"2c7b5eb87b2b288cdbde825f21d2b83b2f5da747"},{"fixed":"a08196c3cc105947746ec21309edfbb60275fcdb"},{"fixed":"1a35da325cac4d5bcad76a2aa943408a6f1d9000"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74666.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.2.0"},{"fixed":"6.6.152"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.104"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.45"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-74666.json"}}],"schema_version":"1.9.0"}