On Wed, Jun 26, 2019 at 10:27:08AM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: abf02e29 Merge tag 'pm-5.2-rc6' of git://git.kernel.org/pu.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=1435aaf6a00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e5c77f8090a3b96b > dashboard link: https://syzkaller.appspot.com/bug?extid=4bfbbf28a2e50ab07368 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11234c41a00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15d7f026a00000 > > The bug was bisected to: > > commit 0c81ea5db25986fb2a704105db454a790c59709c > Author: Elad Raz <eladr@xxxxxxxxxxxx> > Date: Fri Oct 28 19:35:58 2016 +0000 > > mlxsw: core: Add port type (Eth/IB) set API Um, so this doesn't pass the laugh test. > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10393a89a00000 It looks like the automated bisection machinery got confused by two failures getting triggered by the same repro; the symptoms changed over time. Initially, the failure was: crashed: INFO: rcu detected stall in {sys_sendfile64,ext4_file_write_iter} Later, the failure changed to something completely different, and much earlier (before the test was even started): run #5: 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-executor216456474" "root@10.128.15.205:./syz-executor216456474"]: exit status 1 Connection timed out during banner exchange lost connection Looks like an opportunity to improve the bisection engine? - Ted
