On Thu, Dec 6, 2018 at 8:51 PM syzbot <syzbot+df28818b7ebe8e7d704e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: d08970904582 Merge tag 'for-4.20-rc5-tag' of git://git.ker.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=106a5dd5400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=b9cc5a440391cbfd > dashboard link: https://syzkaller.appspot.com/bug?extid=df28818b7ebe8e7d704e > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > userspace arch: i386 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12940cfb400000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16fb5e25400000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+df28818b7ebe8e7d704e@xxxxxxxxxxxxxxxxxxxxxxxxx Since this involves OOMs: #syz dup: kernel panic: corrupted stack end in wb_workfn > kmem_cache 161KB 165KB > Out of memory: Kill process 7764 (syz-executor613) score 0 or sacrifice > child > Killed process 7770 (syz-executor613) total-vm:18964kB, anon-rss:2124kB, > file-rss:4kB, shmem-rss:0kB > oom_reaper: reaped process 7770 (syz-executor613), now anon-rss:0kB, > file-rss:0kB, shmem-rss:0kB > ================================================================== > BUG: KASAN: stack-out-of-bounds in schedule_debug kernel/sched/core.c:3284 > [inline] > BUG: KASAN: stack-out-of-bounds in __schedule+0x1c1b/0x21d0 > kernel/sched/core.c:3394 > Read of size 8 at addr ffff8881ce710000 by task kworker/u4:4/2620 > > CPU: 1 PID: 2620 Comm: kworker/u4:4 Not tainted 4.20.0-rc5+ #266 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: writeback wb_workfn (flush-8:0) > Call Trace: > > The buggy address belongs to the page: > page:ffffea000739c400 count:1 mapcount:0 mapping:0000000000000000 index:0x0 > flags: 0x2fffc0000000000() > raw: 02fffc0000000000 dead000000000100 dead000000000200 0000000000000000 > raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881ce70ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 > ffff8881ce70ff80: f1 00 00 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 > > ffff8881ce710000: f2 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 > ^ > ffff8881ce710080: f2 00 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 > ffff8881ce710100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ================================================================== > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 2620 Comm: kworker/u4:4 Tainted: G B 4.20.0-rc5+ > #266 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: writeback wb_workfn (flush-8:0) > Call Trace: > oom_reaper: reaped process 7789 (syz-executor613), now anon-rss:0kB, > file-rss:0kB, shmem-rss:0kB > rsyslogd invoked oom-killer: gfp_mask=0x6200ca(GFP_HIGHUSER_MOVABLE), > nodemask=(null), order=0, oom_score_adj=0 > rsyslogd cpuset=/ mems_allowed=0 > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches
