On Fri 27-10-17 02:22:40, syzbot wrote: > Hello, > > syzkaller hit the following crash on > a31cc455c512f3f1dd5f79cac8e29a7c8a617af8 > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached.
I do not see such a commit. My linux-next top is next-20171018 [...] > Chain exists of: > cpu_hotplug_lock.rw_sem --> &pipe->mutex/1 --> &sb->s_type->i_mutex_key#9 > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&sb->s_type->i_mutex_key#9); > lock(&pipe->mutex/1); > lock(&sb->s_type->i_mutex_key#9); > lock(cpu_hotplug_lock.rw_sem); I am quite confused about this report. Where exactly is the deadlock? I do not see where we would get pipe mutex from inside of the hotplug lock. Is it possible this is just a false possitive due to cross release feature? -- Michal Hocko SUSE Labs
