In the Linux kernel, the following vulnerability has been resolved:
bna: prevent IOC timer rearm during teardown
bna: prevent IOC timer rearm during teardown
bnad_pci_remove() and the probe disable_ioceth path call
timer_delete_sync() for ioc_timer, sem_timer and hb_timer, but not for
iocpf_timer. bnad_iocpf_timeout() then takes bnad->bna_lock after
free_netdev() has freed the struct bnad.
Deleting iocpf_timer last does not fix this. sem_timer and
iocpf_timer rearm each other: bnad_iocpf_sem_timeout() can arm
iocpf_timer, and bnad_iocpf_timeout() arms sem_timer from
bfa_ioc_hw_sem_get() when the semaphore is busy.
timer_delete_sync() only waits out its own callback.
bnad_ioceth_disable() can time out and leave that callback live.
Shut all four IOC timers down with timer_shutdown_sync() on both
paths, so a later mod_timer() is ignored.
This issue was identified during our ongoing static-analysis research
while reviewing kernel code.