should_failslab+0x5/0x10 mm/slab_common.c:1590 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x277/0x370 mm/slab.c:3557 kmem_cache_zalloc include/linux/slab.h:699 [inline] mmu_topup_memory_cache arch/x86/kvm/mmu.c:996 [inline] mmu_topup_memory_cache arch/x86/kvm/mmu.c:988 [inline] mmu_topup_memory_caches+0x8f/0x370 arch/x86/kvm/mmu.c:1042 ================================================================== kvm_mmu_load+0x1e/0x1200 arch/x86/kvm/mmu.c:5111 BUG: KASAN: use-after-free in kvm_vm_ioctl_unregister_coalesced_mmio+0x25a/0x2c0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:178 Read of size 8 at addr ffff8880a16d3f00 by task syz-executor.5/13972 kvm_mmu_reload arch/x86/kvm/mmu.h:86 [inline] vcpu_enter_guest arch/x86/kvm/x86.c:7724 [inline] vcpu_run arch/x86/kvm/x86.c:7920 [inline] kvm_arch_vcpu_ioctl_run+0x4e5e/0x6f70 arch/x86/kvm/x86.c:8120 kvm_vcpu_ioctl+0x493/0xe10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2847 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f2381f95279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f238090a168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f23820a7f80 RCX: 00007f2381f95279 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f238090a1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd9ff3fa0f R14: 00007f238090a300 R15: 0000000000022000 CPU: 0 PID: 13972 Comm: syz-executor.5 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 kvm_vm_ioctl_unregister_coalesced_mmio+0x25a/0x2c0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:178 kvm_vm_ioctl+0x532/0x1700 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3276 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7efc509d2279 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007efc4f347168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007efc50ae4f80 RCX: 00007efc509d2279 RDX: 00000000200001c0 RSI: 000000004010ae68 RDI: 0000000000000004 RBP: 00007efc4f3471d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc91766f3f R14: 00007efc4f347300 R15: 0000000000022000 Allocated by task 13972: kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] kvm_vm_ioctl_register_coalesced_mmio+0x51/0x350 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:146 kvm_vm_ioctl+0xc63/0x1700 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3267 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 13972: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 kvm_iodevice_destructor include/kvm/iodev.h:73 [inline] kvm_io_bus_unregister_dev.cold+0xf0/0x110 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3899 kvm_vm_ioctl_unregister_coalesced_mmio+0x1be/0x2c0 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:180 kvm_vm_ioctl+0x532/0x1700 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3276 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a16d3f00 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff8880a16d3f00, ffff8880a16d3f40) The buggy address belongs to the page: page:ffffea000285b4c0 count:1 mapcount:0 mapping:ffff88813bff0340 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffffea0002781248 ffffea0002c1bb08 ffff88813bff0340 raw: 0000000000000000 ffff8880a16d3000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a16d3e00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8880a16d3e80: 00 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc >ffff8880a16d3f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8880a16d3f80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8880a16d4000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================