On Thu, Dec 6, 2018 at 10:01 AM syzbot <syzbot+af22f34edec5361fb143@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 6f0597832d81 kmsan: unpoison data passed to skb_put_xxx() .. > git tree: https://github.com/google/kmsan.git/master > console output: https://syzkaller.appspot.com/x/log.txt?x=10b6da5d400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=9b071100dcf8e641 > dashboard link: https://syzkaller.appspot.com/bug?extid=af22f34edec5361fb143 > compiler: clang version 8.0.0 (trunk 348261) > > 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+af22f34edec5361fb143@xxxxxxxxxxxxxxxxxxxxxxxxx #syz dup: KMSAN: kernel-infoleak in kvm_vcpu_write_guest_page > ================================================================== > BUG: KMSAN: kernel-infoleak in __copy_to_user include/linux/uaccess.h:121 > [inline] > BUG: KMSAN: kernel-infoleak in __kvm_write_guest_page+0x2cc/0x4a0 > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1855 > CPU: 1 PID: 17704 Comm: syz-executor1 Not tainted 4.20.0-rc5+ #107 > 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+0x32d/0x480 lib/dump_stack.c:113 > kmsan_report+0x12d/0x290 mm/kmsan/kmsan.c:683 > kmsan_internal_check_memory+0x9ce/0xa50 mm/kmsan/kmsan.c:769 > kmsan_copy_to_user+0x8d/0xa0 mm/kmsan/kmsan_hooks.c:634 > __copy_to_user include/linux/uaccess.h:121 [inline] > __kvm_write_guest_page+0x2cc/0x4a0 > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1855 > kvm_vcpu_write_guest_page+0x196/0x1e0 > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1876 > nested_release_vmcs12 arch/x86/kvm/vmx.c:8489 [inline] > handle_vmptrld+0x1613/0x1750 arch/x86/kvm/vmx.c:9328 > vmx_handle_exit+0x213b/0xb920 arch/x86/kvm/vmx.c:10632 > vcpu_enter_guest arch/x86/kvm/x86.c:7811 [inline] > vcpu_run arch/x86/kvm/x86.c:7874 [inline] > kvm_arch_vcpu_ioctl_run+0xa551/0x11150 arch/x86/kvm/x86.c:8074 > kvm_vcpu_ioctl+0x1098/0x1e30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596 > do_vfs_ioctl+0xf36/0x2d30 fs/ioctl.c:46 > ksys_ioctl fs/ioctl.c:713 [inline] > __do_sys_ioctl fs/ioctl.c:720 [inline] > __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718 > __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718 > do_syscall_64+0xcd/0x110 arch/x86/entry/common.c:291 > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > RIP: 0033:0x457569 > Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f0d0d3f0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 > RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006 > RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0d0d3f16d4 > R13: 00000000004c034e R14: 00000000004d0bc0 R15: 00000000ffffffff > > Uninit was created at: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline] > kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:169 > kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:186 > kmem_cache_alloc_trace+0x6b7/0xe20 mm/slub.c:2789 > kmalloc include/linux/slab.h:546 [inline] > enter_vmx_operation+0x105/0xe10 arch/x86/kvm/vmx.c:8315 > vmx_set_nested_state+0xdc9/0x18a0 arch/x86/kvm/vmx.c:14922 > kvm_arch_vcpu_ioctl+0x4d99/0x7370 arch/x86/kvm/x86.c:4190 > kvm_vcpu_ioctl+0xcf3/0x1e30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2748 > do_vfs_ioctl+0xf36/0x2d30 fs/ioctl.c:46 > ksys_ioctl fs/ioctl.c:713 [inline] > __do_sys_ioctl fs/ioctl.c:720 [inline] > __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718 > __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718 > do_syscall_64+0xcd/0x110 arch/x86/entry/common.c:291 > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > > Bytes 1000-4095 of 4096 are uninitialized > Memory access of size 4096 starts at ffff8881147db000 > Data copied to user address 0000000020feb000 > ================================================================== > > > --- > 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/000000000000ff9610057c56bcd7%40google.com. > For more options, visit https://groups.google.com/d/optout.
