bisecting fixing commit since ae4b064e2a616b545acf02b8f50cc513b32c7522
building syzkaller on 08003f6440deafc4e193b159c4acece64f7864b1
testing commit ae4b064e2a616b545acf02b8f50cc513b32c7522 with gcc (GCC) 8.1.0
kernel signature: 9b529377a9e4d137b668839cd1418427233f5a3cba872be08ae8510e756f1e36
run #0: basic kernel testing failed: failed to copy test binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "-i" "/syzkaller/jobs/linux/workdir/image/key" "/tmp/syz-executor197209141" "root@10.128.0.55:./syz-executor197209141"]: exit status 1
ssh: connect to host 10.128.0.55 port 22: Connection timed out
lost connection

run #1: crashed: INFO: rcu detected stall in chrdev_open
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in corrupted
run #4: crashed: INFO: rcu detected stall in chrdev_open
run #5: crashed: INFO: rcu detected stall in chrdev_open
run #6: crashed: INFO: rcu detected stall in corrupted
run #7: crashed: INFO: rcu detected stall in chrdev_open
run #8: crashed: INFO: rcu detected stall in corrupted
run #9: crashed: INFO: rcu detected stall in corrupted
testing current HEAD c85fb28b6f999db9928b841f63f1beeb3074eeca
testing commit c85fb28b6f999db9928b841f63f1beeb3074eeca with gcc (GCC) 8.1.0
kernel signature: 74ae31b23947ec1f1d4b954b780644d89fbb05052360624702af3178e78e03a8
run #0: crashed: INFO: rcu detected stall in corrupted
run #1: crashed: INFO: rcu detected stall in corrupted
run #2: crashed: INFO: rcu detected stall in corrupted
run #3: crashed: INFO: rcu detected stall in corrupted
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: INFO: rcu detected stall in corrupted
run #6: crashed: INFO: rcu detected stall in chrdev_open
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in chrdev_open
run #9: crashed: INFO: rcu detected stall in corrupted
revisions tested: 2, total time: 21m57.427667005s (build: 11m20.311794276s, test: 9m39.68982695s)
the crash still happens on HEAD
commit msg: Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
crash: INFO: rcu detected stall in corrupted
hrtimer: interrupt took 29979 ns
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=4409, q=961)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294952453-4294941950), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g4409 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:14416 pid:   10 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0x404/0x8a0 kernel/sched/core.c:4527
 schedule+0x3b/0xf0 kernel/sched/core.c:4602
 schedule_timeout+0x1ae/0x2d0 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1890 [inline]
 rcu_gp_kthread+0x702/0xc70 kernel/rcu/tree.c:2060
 kthread+0x160/0x180 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294