================================================================== BUG: KASAN: use-after-free in __list_add include/linux/list.h:64 [inline] BUG: KASAN: use-after-free in list_add include/linux/list.h:79 [inline] BUG: KASAN: use-after-free in irq_bypass_register_consumer+0x51e/0x550 virt/lib/irqbypass.c:217 Write of size 8 at addr ffff8801c95c44a8 by task syz-executor7/20928 CPU: 0 PID: 20928 Comm: syz-executor7 Not tainted 4.18.0-rc5+ #149 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:438 __list_add include/linux/list.h:64 [inline] list_add include/linux/list.h:79 [inline] irq_bypass_register_consumer+0x51e/0x550 virt/lib/irqbypass.c:217 kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:417 [inline] kvm_irqfd+0x198e/0x1ef0 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 kvm_vm_ioctl+0xf80/0x1d80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3015 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: 0033:0x455ab9 Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd5d8f3fc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd5d8f406d4 RCX: 0000000000455ab9 RDX: 00000000200015c0 RSI: 000000004020ae76 RDI: 0000000000000015 RBP: 000000000072bff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bdbc5 R14: 00000000004cc5e0 R15: 0000000000000002 Allocated by task 20928: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:707 [inline] kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:296 [inline] kvm_irqfd+0x18f/0x1ef0 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 kvm_vm_ioctl+0xf80/0x1d80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3015 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 Freed by task 4904: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 irqfd_shutdown+0x144/0x1c0 arch/x86/kvm/../../../virt/kvm/eventfd.c:148 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 The buggy address belongs to the object at ffff8801c95c4340 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff8801c95c4340, ffff8801c95c4540) The buggy address belongs to the page: page:ffffea0007257100 count:1 mapcount:0 mapping:ffff8801da800940 index:0xffff8801c95c4ac0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea00075e86c8 ffffea00072e9d88 ffff8801da800940 raw: ffff8801c95c4ac0 ffff8801c95c40c0 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c95c4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c95c4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c95c4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c95c4500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801c95c4580: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================