On Tue, Dec 19, 2017 at 04:25:01AM -0800, syzbot wrote: > syzkaller has found reproducer for the following crash on > f3b5ad89de16f5d42e8ad36fbdf85f705c1ae051 > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 37s! > BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=-20 stuck for 32s! > Showing busy workqueues and worker pools: > workqueue events: flags=0x0 > pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 > pending: cache_reap > workqueue events_power_efficient: flags=0x80 > pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 > pending: neigh_periodic_work, do_cache_clean > workqueue mm_percpu_wq: flags=0x8 > pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 > pending: vmstat_update > workqueue kblockd: flags=0x18 > pwq 3: cpus=1 node=0 flags=0x0 nice=-20 active=1/256 > pending: blk_timeout_work > The bug that this reproducer reproduces was fixed a while ago by commit 966031f340185e, so I'm marking this bug report fixed by it: #syz fix: n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD) Note that the error message was not always "BUG: workqueue lockup"; it was also sometimes like "watchdog: BUG: soft lockup - CPU#5 stuck for 22s!". syzbot still is hitting the "BUG: workqueue lockup" error sometimes, but it must be for other reasons. None has a reproducer currently. - Eric
