================================================================== 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 ==================================================================