================================================================== 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+0x515/0x530 virt/lib/irqbypass.c:217 Write of size 8 at addr ffff8801c8962228 by task syz-executor625/4509 CPU: 0 PID: 4509 Comm: syz-executor625 Not tainted 4.17.0-rc5+ #58 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+0x1b9/0x294 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+0x515/0x530 virt/lib/irqbypass.c:217 kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:417 [inline] kvm_irqfd+0x1599/0x1ec0 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 kvm_vm_ioctl+0xf84/0x1d90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2997 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16a0 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+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4457d9 RSP: 002b:00007f52fb7b6da8 EFLAGS: 00000297 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006dac44 RCX: 00000000004457d9 RDX: 0000000020000180 RSI: 000000004020ae76 RDI: 00000000000003a9 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac40 R13: 6d766b2f7665642f R14: 00007f52fb7b79c0 R15: 0000000000000007 Allocated by task 4509: 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:512 [inline] kzalloc include/linux/slab.h:701 [inline] kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:296 [inline] kvm_irqfd+0x187/0x1ec0 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 kvm_vm_ioctl+0xf84/0x1d90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2997 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x16a0 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+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 18: 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+0x13a/0x1a0 arch/x86/kvm/../../../virt/kvm/eventfd.c:148 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 The buggy address belongs to the object at ffff8801c89620c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff8801c89620c0, ffff8801c89622c0) The buggy address belongs to the page: page:ffffea0007225880 count:1 mapcount:0 mapping:ffff8801c89620c0 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801c89620c0 0000000000000000 0000000100000006 raw: ffffea0006b676a0 ffffea0006d7c5a0 ffff8801da800940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c8962100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c8962180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c8962200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c8962280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801c8962300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================