On Wed, Aug 22, 2018 at 8:28 AM syzbot <syzbot+bba49d73fe3404646a7b@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 0214f46b3a03 Merge branch 'siginfo-linus' of git://git.ker.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11bc9c2e400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=214e4990bd49329f > dashboard link: https://syzkaller.appspot.com/bug?extid=bba49d73fe3404646a7b > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+bba49d73fe3404646a7b@xxxxxxxxxxxxxxxxxxxxxxxxx > > kvm [9433]: vcpu0, guest rIP: 0x20e disabled perfctr wrmsr: 0x187 data > 0x60000000800 > list_add corruption. next->prev should be prev (ffff8801db01d130), but was > dead000000000200. (next=ffff8801947fdaa0). > ------------[ cut here ]------------ > kernel BUG at lib/list_debug.c:25! > invalid opcode: 0000 [#1] SMP KASAN > CPU: 0 PID: 9519 Comm: syz-executor2 Not tainted 4.18.0+ #201 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:__list_add_valid.cold.0+0xf/0x25 lib/list_debug.c:23 > Code: e8 93 f5 5b fe e9 68 ff ff ff e8 89 f5 5b fe eb c9 4c 89 e7 e8 7f f5 > 5b fe eb 97 48 89 d9 48 c7 c7 e0 9b 3a 87 e8 32 d8 03 fe <0f> 0b 48 89 f1 > 48 c7 c7 a0 9c 3a 87 48 89 de e8 1e d8 03 fe 0f 0b > RSP: 0018:ffff88018f9bf058 EFLAGS: 00010082 > RAX: 0000000000000075 RBX: ffff8801947fdaa0 RCX: ffffc9000200d000 > RDX: 0000000000000000 RSI: ffffffff8163a441 RDI: 0000000000000001 > RBP: ffff88018f9bf070 R08: ffff880196e3a2c0 R09: ffffed003b605008 > R10: ffffed003b605008 R11: ffff8801db028047 R12: ffff8801947fdaa0 > R13: ffff8801947f8300 R14: ffff8801947fdaa0 R15: ffff8801db01d130 > FS: 00007ff35b75e700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fcb6c09b000 CR3: 00000001ca309000 CR4: 00000000001426f0 > Call Trace: > __list_add include/linux/list.h:60 [inline] > list_add include/linux/list.h:79 [inline] > vmx_vcpu_load+0x205/0xfe0 arch/x86/kvm/vmx.c:3061 Let's do: #syz dup: KASAN: use-after-free Read in vmx_vcpu_load Both are in the same function and appeared roughly at the same time. > kvm_arch_vcpu_load+0x22b/0x940 arch/x86/kvm/x86.c:3106 > kvm_sched_in+0x82/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3970 > __fire_sched_in_preempt_notifiers kernel/sched/core.c:2481 [inline] > fire_sched_in_preempt_notifiers kernel/sched/core.c:2487 [inline] > finish_task_switch+0x50d/0x870 kernel/sched/core.c:2679 > context_switch kernel/sched/core.c:2828 [inline] > __schedule+0x884/0x1df0 kernel/sched/core.c:3473 > preempt_schedule_common+0x22/0x60 kernel/sched/core.c:3597 > _cond_resched+0x1d/0x30 kernel/sched/core.c:4963 > slab_pre_alloc_hook mm/slab.h:421 [inline] > slab_alloc mm/slab.c:3378 [inline] > kmem_cache_alloc+0x292/0x710 mm/slab.c:3552 > alloc_inode+0xb2/0x190 fs/inode.c:212 > new_inode_pseudo+0x71/0x1a0 fs/inode.c:903 > new_inode+0x1c/0x40 fs/inode.c:932 > debugfs_get_inode+0x19/0x120 fs/debugfs/inode.c:37 > __debugfs_create_file+0xb5/0x400 fs/debugfs/inode.c:352 > debugfs_create_file+0x57/0x70 fs/debugfs/inode.c:399 > kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:615 > [inline] > kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3209 > [inline] > kvm_dev_ioctl+0xbf5/0x1b10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3236 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:500 [inline] > do_vfs_ioctl+0x1de/0x1720 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+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x457089 > Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ff35b75dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007ff35b75e6d4 RCX: 0000000000457089 > RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000006 > RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff > R13: 00000000004ce9b8 R14: 00000000004c50d7 R15: 0000000000000000 > Modules linked in: > Dumping ftrace buffer: > (ftrace buffer empty) > ---[ end trace a4f093c8080a0418 ]--- > RIP: 0010:__list_add_valid.cold.0+0xf/0x25 lib/list_debug.c:23 > Code: e8 93 f5 5b fe e9 68 ff ff ff e8 89 f5 5b fe eb c9 4c 89 e7 e8 7f f5 > 5b fe eb 97 48 89 d9 48 c7 c7 e0 9b 3a 87 e8 32 d8 03 fe <0f> 0b 48 89 f1 > 48 c7 c7 a0 9c 3a 87 48 89 de e8 1e d8 03 fe 0f 0b > RSP: 0018:ffff88018f9bf058 EFLAGS: 00010082 > RAX: 0000000000000075 RBX: ffff8801947fdaa0 RCX: ffffc9000200d000 > RDX: 0000000000000000 RSI: ffffffff8163a441 RDI: 0000000000000001 > RBP: ffff88018f9bf070 R08: ffff880196e3a2c0 R09: ffffed003b605008 > R10: ffffed003b605008 R11: ffff8801db028047 R12: ffff8801947fdaa0 > R13: ffff8801947f8300 R14: ffff8801947fdaa0 R15: ffff8801db01d130 > FS: 00007ff35b75e700(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fcb6c09b000 CR3: 00000001ca309000 CR4: 00000000001426f0 > > > --- > 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. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009972a10574003ef3%40google.com. > For more options, visit https://groups.google.com/d/optout.
