{"id":"CVE-2026-98619","published":"2026-10-18T16:17:14.787","lastModified":"2026-10-19T10:19:26.000","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ethtool: keep rtnl_lock for the ioctl self test\n\nAn offline self test that brings the interface down and back up with\nnetif_close() / netif_open() requires rtnl_lock for both. Since the\nethtool IOCTL path became rtnl-optional for ops-locked drivers, the\nETHTOOL_TEST ioctl runs holding only the netdev instance lock, so on an\nops-locked driver the self test now tears the device down without\nrtnl_lock.\n\nWith lockdep this reproduces deterministically on every offline self\ntest on such a driver; note the sole lock held is the instance lock, not\nrtnl:\n\n  WARNING: suspicious RCU usage\n  net/core/netpoll.c:207 suspicious rcu_dereference_protected() usage!\n  1 lock held by ethtool/107:\n   #0: (&dev->lock){+.+.}, at: dev_ethtool\n  Call Trace:\n   netpoll_poll_disable\n   __dev_close_many\n   netif_close_many\n   netif_close\n   fbnic_self_test\n   dev_ethtool_locked\n   dev_ethtool\n   dev_ioctl\n   sock_ioctl\n   __x64_sys_ioctl\n\nWithout lockdep the same condition trips ASSERT_RTNL() in\n__dev_close_many() / __dev_open(); that check only samples the global\nrtnl state, so it can be masked by a concurrent rtnl holder, but the\ndevice is still being reconfigured without the lock it requires.\n\nThe ethtool self_test is a legacy ioctl-only command, so an ETHTOOL_TEST\ncase is only needed on the ioctl path. Add an opt-in bit for drivers whose\nself test needs rtnl_lock and set it on the ops-locked drivers whose\noffline self test tears the interface down and up:\n\n  - fbnic (ops-locked via queue_mgmt_ops): fbnic_self_test() offline path\n    uses netif_close() / netif_open().\n  - bnxt (ops-locked via queue_mgmt_ops): bnxt_self_test() offline path\n    goes through bnxt_close_nic() / bnxt_half_open_nic() /\n    bnxt_half_close_nic() / bnxt_open_nic(), which close and reopen the\n    device.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/1b82958f3f035df5ccaab5430a2302f08a5d5351","tags":[]},{"url":"https://git.kernel.org/stable/c/4ca1503491f1f25a954c13ac5775bf6775c5abc8","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}