{"id":"AZL-96096","summary":"CVE-2026-74523 affecting package kernel 6.6.150.1-1","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-\u003eqede_lock)        \u003c- taken\n   qede_recovery_handler\n    qede_load\n    udp_tunnel_nic_reset_ntf\n     __udp_tunnel_nic_device_sync\n      info-\u003esync_table == qede_udp_tunnel_sync\n       mutex_lock(&edev-\u003eqede_lock)    \u003c- 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.","modified":"2026-08-30T05:26:50Z","published":"2026-08-15T13:17:57Z","upstream":["CVE-2026-74523"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74523"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-96096.json"}}],"schema_version":"1.9.0"}