Re: [QUESTION] Hung task warning while running syzkaller test

[Valentin Schneider]

Hi,

On 14/10/2019 08:03, Zhihao Cheng wrote:
> Hi, everyone. We met a hung task problem while running syzkaller test. The stacks of hung tasks vary in net/fs/sched, and we provide a stable reproduce test case in fs. The higher the kernel version, the lower the probability of reproduce. Maybe the mainline has gradually optimized the scheduling and mutex.
> 
> Environment:
> 	A. qemu(x86_64 8-core 16GB-RAM)
> 	B. physical machine (x86_64 8-core 314GB-RAM)
> 
> 	./syz-execprog -executor=/home/abc/syz-executor -repeat=0 -procs=16 -cover=0 repro
> repro is a configuration file containing syzkaller execution instructions, which shown as follows:
> 	syz_execute_func(&(0x7f0000000140)="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")
> 	socket(0x1, 0x80000, 0x4)
> 

I did try to run that but kept hitting cgroup config options that aren't
enabled in my defconfig - I gave up after net_cls, net_prio and the freezer.

Could you please share your .config?