On 4/6/18 7:02 AM, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 38c23685b273cfb4ccf31a199feccce3bdcb5d83 (Fri Apr 6 04:29:35 2018 +0000) > Merge tag 'armsoc-drivers' of > git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=31e8daa8b3fc129e75f2 > > So far this crash happened 9 times on upstream. > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6407930337296384 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=4942413340606464 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=4764483918495744 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-5813481738265533882 > compiler: gcc (GCC) 8.0.1 20180301 (experimental) > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+31e8daa8b3fc129e75f2@xxxxxxxxxxxxxxxxxxxxxxxxx > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > > ================================================ > WARNING: lock held when returning to user space! > 4.16.0+ #3 Not tainted > ------------------------------------------------ > syzkaller433111/4462 is leaving the kernel with locks still held! > 1 lock held by syzkaller433111/4462: > #0: 0000000003a06fae (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x1ec0 > drivers/block/loop.c:1363 Is this a new regression? Omar did just fiddle with the locking a bit, seems suspicious. -- Jens Axboe
