On Tue, Nov 27, 2018 at 7:14 AM, Wanpeng Li <kernellwp@xxxxxxxxx> wrote: > > On Tue, 27 Nov 2018 at 12:51, syzbot > <syzbot+ff40b9bc4835ea83211c@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > Hello, > > Is there beauty C codes? syzbot does not have code like: if (rand() % 2) send_C_repro(); :) > > syzbot found the following crash on: > > > > HEAD commit: 442b8cea2477 Add linux-next specific files for 20181109 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=174d326d400000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=2f72bdb11df9fbe8 > > dashboard link: https://syzkaller.appspot.com/bug?extid=ff40b9bc4835ea83211c > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14f5df7b400000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+ff40b9bc4835ea83211c@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ================================================================== > > BUG: KASAN: use-after-free in mark_page_dirty_in_slot > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:2056 [inline] > > BUG: KASAN: use-after-free in kvm_write_guest_offset_cached+0x693/0x6b0 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1988 > > Read of size 8 at addr ffff8801b9363778 by task syz-executor1/30438 > > > > CPU: 1 PID: 30438 Comm: syz-executor1 Not tainted 4.20.0-rc1-next-20181109+ > > #110 > > 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+0x244/0x39d lib/dump_stack.c:113 > > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > > kasan_report_error mm/kasan/report.c:354 [inline] > > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > > mark_page_dirty_in_slot arch/x86/kvm/../../../virt/kvm/kvm_main.c:2056 > > [inline] > > kvm_write_guest_offset_cached+0x693/0x6b0 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1988 > > kvm_steal_time_set_preempted arch/x86/kvm/x86.c:3241 [inline] > > kvm_arch_vcpu_put+0x365/0x420 arch/x86/kvm/x86.c:3268 > > kvm_sched_out+0x91/0xb0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3993 > > __fire_sched_out_preempt_notifiers kernel/sched/core.c:2503 [inline] > > fire_sched_out_preempt_notifiers kernel/sched/core.c:2511 [inline] > > prepare_task_switch kernel/sched/core.c:2617 [inline] > > context_switch kernel/sched/core.c:2796 [inline] > > __schedule+0x11ca/0x21d0 kernel/sched/core.c:3472 > > preempt_schedule_irq+0xb9/0x140 kernel/sched/core.c:3699 > > retint_kernel+0x1b/0x2d > > RIP: 0010:search_memslots include/linux/kvm_host.h:955 [inline] > > RIP: 0010:__gfn_to_memslot include/linux/kvm_host.h:976 [inline] > > RIP: 0010:__kvm_gfn_to_hva_cache_init+0x2ed/0xd10 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1935 > > Code: 3c 02 00 0f 85 0d 0a 00 00 4d 03 6c 24 08 48 89 df 4c 89 ee e8 04 16 > > 78 00 4c 39 eb 0f 82 6e 01 00 00 45 31 ed e8 43 15 78 00 <44> 89 fe 44 89 > > ef e8 c8 15 78 00 45 39 fd 0f 8d cf 00 00 00 e8 2a > > RSP: 0018:ffff8801cbfee970 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 > > RAX: ffff8801b9a4c280 RBX: 0000000000000000 RCX: ffffffff8107942f > > RDX: 0000000000000000 RSI: ffffffff8107936d RDI: 0000000000000006 > > RBP: ffff8801cbfeeb60 R08: ffff8801b9a4c280 R09: ffffed00342bb209 > > R10: ffffed00342bb209 R11: ffff8801a15d904b R12: 0000000000000017 > > R13: 0000000000000017 R14: 0000000000000016 R15: 0000000000000017 > > kvm_gfn_to_hva_cache_init+0x15a/0x340 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1963 > > kvm_set_msr_common+0x1a0c/0x2670 arch/x86/kvm/x86.c:2549 > > vmx_set_msr+0x759/0x1f90 arch/x86/kvm/vmx.c:4360 > > kvm_set_msr+0x18a/0x370 arch/x86/kvm/x86.c:1324 > > do_set_msr+0x10d/0x1a0 arch/x86/kvm/x86.c:1353 > > __msr_io arch/x86/kvm/x86.c:2905 [inline] > > msr_io+0x222/0x380 arch/x86/kvm/x86.c:2941 > > kvm_arch_vcpu_ioctl+0x961/0x3b00 arch/x86/kvm/x86.c:3956 > > kvm_vcpu_ioctl+0x278/0x1150 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2748 > > vfs_ioctl fs/ioctl.c:46 [inline] > > file_ioctl fs/ioctl.c:509 [inline] > > do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696 > > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713 > > __do_sys_ioctl fs/ioctl.c:720 [inline] > > __se_sys_ioctl fs/ioctl.c:718 [inline] > > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > 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:00007fc292e62c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 > > RDX: 0000000020000280 RSI: 000000004008ae89 RDI: 0000000000000005 > > RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc292e636d4 > > R13: 00000000004bff9d R14: 00000000004d0970 R15: 00000000ffffffff > > > > Allocated by task 30427: > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > set_track mm/kasan/kasan.c:460 [inline] > > kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 > > __do_kmalloc_node mm/slab.c:3684 [inline] > > __kmalloc_node+0x50/0x70 mm/slab.c:3691 > > kmalloc_node include/linux/slab.h:589 [inline] > > kvmalloc_node+0xb9/0xf0 mm/util.c:416 > > kvmalloc include/linux/mm.h:577 [inline] > > kvzalloc include/linux/mm.h:585 [inline] > > __kvm_set_memory_region+0x116e/0x2d50 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1023 > > kvm_set_memory_region+0x2e/0x50 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1085 > > kvm_vm_ioctl_set_memory_region > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1097 [inline] > > kvm_vm_ioctl+0x652/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2995 > > vfs_ioctl fs/ioctl.c:46 [inline] > > file_ioctl fs/ioctl.c:509 [inline] > > do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696 > > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713 > > __do_sys_ioctl fs/ioctl.c:720 [inline] > > __se_sys_ioctl fs/ioctl.c:718 [inline] > > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > Freed by task 30427: > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > set_track mm/kasan/kasan.c:460 [inline] > > __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 > > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > > __cache_free mm/slab.c:3498 [inline] > > kfree+0xcf/0x230 mm/slab.c:3817 > > kvfree+0x61/0x70 mm/util.c:445 > > __kvm_set_memory_region+0x1cb3/0x2d50 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1067 > > kvm_set_memory_region+0x2e/0x50 > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1085 > > kvm_vm_ioctl_set_memory_region > > arch/x86/kvm/../../../virt/kvm/kvm_main.c:1097 [inline] > > kvm_vm_ioctl+0x652/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2995 > > vfs_ioctl fs/ioctl.c:46 [inline] > > file_ioctl fs/ioctl.c:509 [inline] > > do_vfs_ioctl+0x1de/0x1790 fs/ioctl.c:696 > > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713 > > __do_sys_ioctl fs/ioctl.c:720 [inline] > > __se_sys_ioctl fs/ioctl.c:718 [inline] > > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > The buggy address belongs to the object at ffff8801b9363080 > > which belongs to the cache kmalloc-64k of size 65536 > > The buggy address is located 1784 bytes inside of > > 65536-byte region [ffff8801b9363080, ffff8801b9373080) > > The buggy address belongs to the page: > > page:ffffea0006e4d800 count:1 mapcount:0 mapping:ffff8801da802500 index:0x0 > > compound_mapcount: 0 > > flags: 0x2fffc0000010200(slab|head) > > raw: 02fffc0000010200 ffffea0006906808 ffffea0007034808 ffff8801da802500 > > raw: 0000000000000000 ffff8801b9363080 0000000100000001 0000000000000000 > > page dumped because: kasan: bad access detected > > > > Memory state around the buggy address: > > ffff8801b9363600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801b9363680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > > ffff8801b9363700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff8801b9363780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8801b9363800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > > > > > --- > > 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 > > -- > 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/CANRm%2BCykdB1-g0j0y%2B2AngDBkdeX%3DL4c6KxF_Yup4EN0QTJpEA%40mail.gmail.com. > For more options, visit https://groups.google.com/d/optout.
