Hi Jakub, Jakub Kicinski <k...@kernel.org> writes:
> On Tue, 08 Sep 2020 22:29:21 -0700 syzbot wrote: >> Hello, >> >> syzbot found the following issue on: >> >> HEAD commit: 59126901 Merge tag 'perf-tools-fixes-for-v5.9-2020-09-03' .. >> git tree: upstream >> console output: https://syzkaller.appspot.com/x/log.txt?x=12edb935900000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=3c5f6ce8d5b68299 >> dashboard link: https://syzkaller.appspot.com/bug?extid=8267241609ae8c23b248 >> compiler: gcc (GCC) 10.1.0-syz 20200507 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=157c7aa5900000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13c92ef9900000 >> >> The issue was bisected to: >> >> commit 5a781ccbd19e4664babcbe4b4ead7aa2b9283d22 >> Author: Vinicius Costa Gomes <vinicius.go...@intel.com> >> Date: Sat Sep 29 00:59:43 2018 +0000 >> >> tc: Add support for configuring the taprio scheduler > > > Vinicius, could you please take a look at all the syzbot reports which > point to your commit? I know syzbot bisection is not super reliable, > but at least 3 reports point to your commit now, so something's > probably going on. I did take a look, and it seems that it all boils down to having too small (unreasonable?) intervals in the schedule, which causes the hrtimer handler to starve the other kernel threads. I have a quick fix to restrict the interval values to more sensible values (at least equal to the time it takes to transmit the mininum ethernet frame size), I am testing it and I will propose it soon. But a proper solution will require more time. Cheers, -- Vinicius
