On 29/04/2018 19:00, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > bf8f5de17442bba5f811e7e724980730e079ee11 (Sat Apr 28 17:05:04 2018 +0000) > MAINTAINERS: add myself as maintainer of AFFS > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=35666cba7f0a337e2e79 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5686569910403072 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=5767017265102848 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=6346308495343616 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=7043958930931867332 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+35666cba7f0a337e2e79@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. > > ------------[ cut here ]------------ > DEBUG_LOCKS_WARN_ON(__owner_task(owner) != current) > WARNING: CPU: 0 PID: 4525 at kernel/locking/mutex.c:1032 > __mutex_unlock_slowpath+0x62e/0x8a0 kernel/locking/mutex.c:1032 > Kernel panic - not syncing: panic_on_warn set ... This doesn't make much sense, unless it's a "generic" memory corruption, but at least the reproducer seems to be simple, just (in pseudocode) ioctl(kvm_vm_fd, KVM_HYPERV_EVENTFD, { fd = some_eventfd, conn_id = 0, flags = 0 }) ioctl(kvm_vm_fd, KVM_HYPERV_EVENTFD, { fd = -1, conn_id = 5, flags = KVM_HYPERV_EVENTFD_DEASSIGN }) Roman, Cathy, can you give it a quick look? (Reproducing the reproducer link: https://syzkaller.appspot.com/x/repro.c?id=5686569910403072). Paolo > CPU: 0 PID: 4525 Comm: syz-executor809 Not tainted 4.17.0-rc2+ #22 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1b9/0x294 lib/dump_stack.c:113 > panic+0x22f/0x4de kernel/panic.c:184 > __warn.cold.8+0x163/0x1b3 kernel/panic.c:536 > report_bug+0x252/0x2d0 lib/bug.c:186 > fixup_bug arch/x86/kernel/traps.c:178 [inline] > do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296 > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 > RIP: 0010:__mutex_unlock_slowpath+0x62e/0x8a0 kernel/locking/mutex.c:1032 > RSP: 0018:ffff8801cf31f138 EFLAGS: 00010286 > RAX: 0000000000000033 RBX: 1ffff10039e63e30 RCX: ffffffff8160b82d > RDX: 0000000000000000 RSI: ffffffff816104e1 RDI: 0000000000000001 > RBP: ffff8801cf31f2a8 R08: ffff8801d9042180 R09: fffffbfff11b0974 > R10: fffffbfff11b0974 R11: ffffffff88d84ba3 R12: ffffffff8a713a20 > R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801989d6b08 > mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614 > kvm_hv_eventfd_deassign arch/x86/kvm/hyperv.c:1434 [inline] > kvm_vm_ioctl_hv_eventfd+0x1ea/0x24b arch/x86/kvm/hyperv.c:1451 > kvm_arch_vm_ioctl+0x155e/0x2690 arch/x86/kvm/x86.c:4563 > kvm_vm_ioctl+0x246/0x1d90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3100 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:500 [inline] > do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684 > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 > __do_sys_ioctl fs/ioctl.c:708 [inline] > __se_sys_ioctl fs/ioctl.c:706 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4401f9 > RSP: 002b:00007ffcd5727a48 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 6d766b2f7665642f RCX: 00000000004401f9 > RDX: 0000000020000140 RSI: 000000004018aebd RDI: 00000000000000ee > RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 > R10: 00000000004002c8 R11: 0000000000000217 R12: 0000000000401720 > R13: 00000000004017b0 R14: 0000000000000000 R15: 0000000000000000 > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body.
