================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3d4d/0x3e00 kernel/locking/lockdep.c:3306 Read of size 8 at addr ffff8801d4c0c2a0 by task syzkaller424624/9009 CPU: 0 PID: 9009 Comm: syzkaller424624 Not tainted 4.15.0-rc9+ #284 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 __lock_acquire+0x3d4d/0x3e00 kernel/locking/lockdep.c:3306 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3915 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 remove_wait_queue+0x81/0x350 kernel/sched/wait.c:50 vhost_poll_stop drivers/vhost/vhost.c:230 [inline] vhost_dev_stop+0x15c/0x2a0 drivers/vhost/vhost.c:566 vhost_net_release+0x6e/0x190 drivers/vhost/net.c:998 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 RIP: 0033:0x44c179 RSP: 002b:00007f9cf134acf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 0000000000700024 RCX: 000000000044c179 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000700024 RBP: 0000000000700020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000080f40f R14: 00007f9cf134b9c0 R15: 0000000000000007 Allocated by task 9009: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610 kmalloc include/linux/slab.h:499 [inline] eventfd_file_create.part.3+0x96/0x250 fs/eventfd.c:441 eventfd_file_create fs/eventfd.c:483 [inline] SYSC_eventfd2 fs/eventfd.c:468 [inline] SyS_eventfd2 fs/eventfd.c:458 [inline] SYSC_eventfd fs/eventfd.c:485 [inline] SyS_eventfd+0x2c/0x80 fs/eventfd.c:483 entry_SYSCALL_64_fastpath+0x29/0xa0 Freed by task 9009: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kfree+0xd6/0x260 mm/slab.c:3803 eventfd_free_ctx fs/eventfd.c:72 [inline] eventfd_free fs/eventfd.c:79 [inline] kref_put include/linux/kref.h:70 [inline] eventfd_ctx_put+0x26/0x30 fs/eventfd.c:104 eventfd_release+0x52/0x60 fs/eventfd.c:113 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 The buggy address belongs to the object at ffff8801d4c0c280 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 32 bytes inside of 96-byte region [ffff8801d4c0c280, ffff8801d4c0c2e0) The buggy address belongs to the page: page:ffffea0007530300 count:1 mapcount:0 mapping:ffff8801d4c0c000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d4c0c000 0000000000000000 0000000100000020 raw: ffffea00076b59e0 ffffea0007539c60 ffff8801dac004c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d4c0c180: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff8801d4c0c200: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff8801d4c0c280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8801d4c0c300: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ffff8801d4c0c380: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ==================================================================