On Fri, Sep 11 2020 at 03:39, syzbot wrote: > > ------------[ cut here ]------------ > syscall 56 left IRQs disabled
Ouch. syscall 56 == sys_clone > WARNING: CPU: 1 PID: 31467 at kernel/entry/common.c:245 > syscall_exit_to_user_mode_prepare kernel/entry/common.c:245 [inline] <snip> > ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:287 But this does not make any sense for regular fork because ret_from_fork() invokes schedule_tail() which drops the runqueue lock and enables interrupts. But for kernel threads that's more interesting because after schedule_tail() the kernel thread function is invoked and this can call kernel_execve() and return to ret_from_fork() and then run through syscall_exit_to_user_mode(). Let me get that reproducer...
