binder: 13427:13433 ioctl c0306201 20022fd0 returned -14 ================================================================== BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] BUG: KASAN: use-after-free in do_raw_spin_lock+0x1e0/0x220 kernel/locking/spinlock_debug.c:112 Read of size 4 at addr ffff8801d55d40a4 by task syz-executor1/13447 CPU: 1 PID: 13447 Comm: syz-executor1 Not tainted 4.15.0+ #305 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:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline] do_raw_spin_lock+0x1e0/0x220 kernel/locking/spinlock_debug.c:112 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline] _raw_spin_lock_irqsave+0x9e/0xc0 kernel/locking/spinlock.c:152 remove_wait_queue+0x81/0x350 kernel/sched/wait.c:50 ep_remove_wait_queue fs/eventpoll.c:595 [inline] ep_unregister_pollwait.isra.7+0x18c/0x590 fs/eventpoll.c:613 ep_free+0x13f/0x320 fs/eventpoll.c:830 ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:862 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ed/0x940 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x26/0x9b RIP: 0033:0x453299 RSP: 002b:00007ffbf4004c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000124 RAX: 0000000000000018 RBX: 000000000071bf58 RCX: 0000000000453299 RDX: 0000000000000000 RSI: 0000000000000018 RDI: 0000000000000017 RBP: 000000000000006d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006efad8 R13: 00000000ffffffff R14: 00007ffbf40056d4 R15: 0000000000000002 Allocated by task 13442: 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:552 kmem_cache_alloc_trace+0x136/0x740 mm/slab.c:3607 kmalloc include/linux/slab.h:512 [inline] kzalloc include/linux/slab.h:701 [inline] binder_get_thread+0x1cf/0x870 drivers/android/binder.c:4279 binder_poll+0x8c/0x390 drivers/android/binder.c:4393 ep_item_poll.isra.10+0xf2/0x320 fs/eventpoll.c:885 ep_insert+0x6a2/0x1ac0 fs/eventpoll.c:1457 SYSC_epoll_ctl fs/eventpoll.c:2104 [inline] SyS_epoll_ctl+0x12bf/0x1a80 fs/eventpoll.c:1990 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b Freed by task 13442: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 __cache_free mm/slab.c:3485 [inline] kfree+0xd9/0x260 mm/slab.c:3800 binder_free_thread drivers/android/binder.c:4306 [inline] binder_thread_dec_tmpref+0x27f/0x310 drivers/android/binder.c:1879 binder_thread_release+0x4a1/0x6b0 drivers/android/binder.c:4382 binder_ioctl+0xc02/0x1417 drivers/android/binder.c:4599 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x26/0x9b The buggy address belongs to the object at ffff8801d55d4000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 164 bytes inside of 512-byte region [ffff8801d55d4000, ffff8801d55d4200) The buggy address belongs to the page: page:ffffea0007557500 count:1 mapcount:0 mapping:ffff8801d55d4000 index:0xffff8801d55d4500 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d55d4000 ffff8801d55d4500 0000000100000005 raw: ffffea00075575e0 ffffea0006cabaa0 ffff8801db000940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d55d3f80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff8801d55d4000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d55d4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d55d4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d55d4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================