{"id":"CVE-2026-74523","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74523","summary":"qede: sync udp_tunnel ports outside qede_lock in the recovery path","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nqede: sync udp_tunnel ports outside qede_lock in the recovery path\n\nA TX timeout on a qede NIC that has VXLAN/GENEVE tunnel ports\nconfigured wedges the rtnetlink control plane of the whole machine:\n\n  NETDEV WATCHDOG: ens6f1 (qede): transmit queue 2 timed out 10226 ms\n  [qede_tx_timeout:586(ens6f1)]TX timeout on queue 2!\n  [qede_recovery_handler:2665(ens6f0)]Starting a recovery process\n\nThe recovery path deadlocks on the driver's own mutex:\n\n  qede_sp_task\n   rtnl_lock()\n   mutex_lock(&edev->qede_lock)        <- taken\n   qede_recovery_handler\n    qede_load\n    udp_tunnel_nic_reset_ntf\n     __udp_tunnel_nic_device_sync\n      info->sync_table == qede_udp_tunnel_sync\n       mutex_lock(&edev->qede_lock)    <- same task: deadlock\n\nThe mutex is not recursive, so the kworker blocks on itself with\nrtnl_lock held, and neither lock is ever released. Every task that\ncalls rtnl_lock() afterwards (ip, ovs-vswitchd, lldpad, IPv6\naddrconf, sshd) blocks forever while the node still answers ping.\nIn a vmcore from an affected production node rtnl_mutex.owner\ndecodes to the very kworker blocked at the innermost mutex_lock()\nabove.\n\nRe-sync the tunnel ports from qede_sp_task() after the internal lock\nis dropped, still under rtnl_lock as the udp_tunnel API requires.\nThis mirrors qede_open(), which calls udp_tunnel_nic_reset_ntf()\nunder rtnl without the internal lock.\n\nqede_recovery_handler() now returns whether it has successfully\nreloaded an open device, and the caller re-syncs the ports only in\nthat case. This keeps the old gating exactly: a device that was down\nor a failed recovery returns false, as those paths never reached the\nudp_tunnel_nic_reset_ntf() call before either.\n\nThis was the only user of the qede_lock()/qede_unlock() helpers, so\nremove them.","published":"2026-08-15T12:27:40.575Z","modified":"2026-08-18T03:56:50.651543418Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.6.151"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/451c9075d6c53f2438d110addbeeeea6fac18567"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4626df3f63c9185efba5750fe76ac01ab3351bae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6f1ef8170d3d8ad9319aa01347945dcdf5cc4f27"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e382a4efeeae6555b95d9ff336cf3094ee7d336b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e51becb8f3377a377171ed5bf0082b96e22e6292"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74523.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74523"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:50.651543418Z"}}