audit: type=1400 audit(1513772884.034:7): avc: denied { map } for pid=3148 comm="syzkaller472024" path="/root/syzkaller472024764" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x465e/0x47f0 kernel/locking/lockdep.c:3378 Read of size 8 at addr ffff8801c4d07378 by task syzkaller472024/3148 CPU: 0 PID: 3148 Comm: syzkaller472024 Not tainted 4.15.0-rc2-mm1+ #39 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+0x465e/0x47f0 kernel/locking/lockdep.c:3378 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:159 remove_wait_queue+0x81/0x350 kernel/sched/wait.c:50 ep_remove_wait_queue fs/eventpoll.c:594 [inline] ep_unregister_pollwait.isra.7+0x18c/0x590 fs/eventpoll.c:612 ep_free+0x135/0x300 fs/eventpoll.c:829 ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:861 __fput+0x333/0x7f0 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/0x1ae0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 SYSC_exit_group kernel/exit.c:983 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:981 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x4429f8 RSP: 002b:00007ffee75fb968 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 00000000004429f8 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000006ce018 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a40 R13: 0000000000401ad0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3148: 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:3614 kmalloc include/linux/slab.h:516 [inline] kzalloc include/linux/slab.h:705 [inline] binder_get_thread+0x1cf/0x870 drivers/android/binder.c:4269 binder_poll+0x8c/0x390 drivers/android/binder.c:4371 ep_item_poll.isra.10+0xf2/0x320 fs/eventpoll.c:884 ep_insert+0x6a2/0x1b50 fs/eventpoll.c:1455 SYSC_epoll_ctl fs/eventpoll.c:2102 [inline] SyS_epoll_ctl+0x129b/0x1a60 fs/eventpoll.c:1988 entry_SYSCALL_64_fastpath+0x1f/0x96 Freed by task 3148: 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:3492 [inline] kfree+0xca/0x250 mm/slab.c:3807 binder_free_thread drivers/android/binder.c:4296 [inline] binder_thread_dec_tmpref+0x27f/0x310 drivers/android/binder.c:1869 binder_thread_release+0x27d/0x540 drivers/android/binder.c:4360 binder_ioctl+0xc05/0x141a drivers/android/binder.c:4577 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x1f/0x96 The buggy address belongs to the object at ffff8801c4d072c0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8801c4d072c0, ffff8801c4d074c0) The buggy address belongs to the page: page:00000000385e870b count:1 mapcount:0 mapping:0000000022ef5bfd index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801c4d07040 0000000000000000 0000000100000006 raw: ffffea0007131360 ffffea0007129260 ffff8801dac00940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c4d07200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c4d07280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8801c4d07300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c4d07380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c4d07400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================