random: sshd: uninitialized urandom read (32 bytes read, 113 bits of entropy available) ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 kernel/locking/lockdep.c:3092 Read of size 8 at addr ffff8800b4561c38 by task syzkaller926737/3303 CPU: 0 PID: 3303 Comm: syzkaller926737 Not tainted 4.4.106-g1700518 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 face907d7a8d95c7 ffff8801d17af850 ffffffff81d02f7d ffffea0002d15800 ffff8800b4561c38 0000000000000000 ffff8800b4561c38 0000000000000000 ffff8801d17af888 ffffffff814fa843 ffff8800b4561c38 Call Trace: [<ffffffff81d02f7d>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff81d02f7d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [<ffffffff814fa843>] print_address_description+0x73/0x260 mm/kasan/report.c:252 [<ffffffff814fad55>] kasan_report_error mm/kasan/report.c:351 [inline] [<ffffffff814fad55>] kasan_report+0x285/0x370 mm/kasan/report.c:408 [<ffffffff814faeb4>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [<ffffffff81236eae>] __lock_acquire+0x387e/0x4b50 kernel/locking/lockdep.c:3092 [<ffffffff812399ee>] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [<ffffffff8376eb3e>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline] [<ffffffff8376eb3e>] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159 [<ffffffff8121c394>] remove_wait_queue+0x14/0x40 kernel/sched/wait.c:49 [<ffffffff815f49f8>] ep_remove_wait_queue fs/eventpoll.c:530 [inline] [<ffffffff815f49f8>] ep_unregister_pollwait.isra.6+0xa8/0x220 fs/eventpoll.c:548 [<ffffffff815f5723>] ep_free+0x93/0x1c0 fs/eventpoll.c:765 [<ffffffff815f5894>] ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:797 [<ffffffff8151fe83>] __fput+0x233/0x6d0 fs/file_table.c:208 [<ffffffff815203a5>] ____fput+0x15/0x20 fs/file_table.c:244 [<ffffffff81188c94>] task_work_run+0x104/0x180 kernel/task_work.c:115 [<ffffffff81130481>] exit_task_work include/linux/task_work.h:21 [inline] [<ffffffff81130481>] do_exit+0x871/0x2a20 kernel/exit.c:755 [<ffffffff811368f8>] do_group_exit+0x108/0x320 kernel/exit.c:885 [<ffffffff81136b2d>] SYSC_exit_group kernel/exit.c:896 [inline] [<ffffffff81136b2d>] SyS_exit_group+0x1d/0x20 kernel/exit.c:894 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [<ffffffff837706d7>] sysenter_flags_fixed+0xd/0x17 Allocated by task 3303: [<ffffffff81035c86>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814f98b3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814f9b7d>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814f9b7d>] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [<ffffffff814f5b30>] kmem_cache_alloc_trace+0x100/0x2b0 mm/slub.c:2642 [<ffffffff82c784f1>] kmalloc include/linux/slab.h:476 [inline] [<ffffffff82c784f1>] kzalloc include/linux/slab.h:620 [inline] [<ffffffff82c784f1>] binder_get_thread+0x181/0x7a0 drivers/android/binder.c:4455 [<ffffffff82c78b5a>] binder_poll+0x4a/0x210 drivers/android/binder.c:4558 [<ffffffff815f8881>] ep_item_poll fs/eventpoll.c:806 [inline] [<ffffffff815f8881>] ep_insert fs/eventpoll.c:1319 [inline] [<ffffffff815f8881>] SYSC_epoll_ctl fs/eventpoll.c:1934 [inline] [<ffffffff815f8881>] SyS_epoll_ctl+0x10b1/0x2050 fs/eventpoll.c:1833 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [<ffffffff837706d7>] sysenter_flags_fixed+0xd/0x17 Freed by task 3303: [<ffffffff81035c86>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [<ffffffff814f98b3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [<ffffffff814fa1d2>] set_track mm/kasan/kasan.c:524 [inline] [<ffffffff814fa1d2>] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [<ffffffff814f6c59>] slab_free_hook mm/slub.c:1383 [inline] [<ffffffff814f6c59>] slab_free_freelist_hook mm/slub.c:1405 [inline] [<ffffffff814f6c59>] slab_free mm/slub.c:2859 [inline] [<ffffffff814f6c59>] kfree+0xe9/0x2f0 mm/slub.c:3749 [<ffffffff82c71a41>] binder_free_thread drivers/android/binder.c:4483 [inline] [<ffffffff82c71a41>] binder_thread_dec_tmpref+0x1c1/0x250 drivers/android/binder.c:2039 [<ffffffff82c7257d>] binder_thread_release+0x27d/0x540 drivers/android/binder.c:4547 [<ffffffff82c8d1f4>] binder_ioctl+0xb94/0x12e0 drivers/android/binder.c:4763 [<ffffffff8161c27a>] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [<ffffffff8161c27a>] compat_SyS_ioctl+0x28a/0x2540 fs/compat_ioctl.c:1544 [<ffffffff81006d84>] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [<ffffffff81006d84>] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [<ffffffff837706d7>] sysenter_flags_fixed+0xd/0x17 The buggy address belongs to the object at ffff8800b4561b80 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8800b4561b80, ffff8800b4561d80) The buggy address belongs to the page: PANIC: double fault, error_code: 0x0 CPU: 0 PID: 3303 Comm: syzkaller926737 Not tainted 4.4.106-g1700518 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d18497c0 task.stack: ffff8801d17a8000 RIP: 0010:[<ffffffff8148d16a>] [<ffffffff8148d16a>] dump_page_badflags+0x1a/0x250 mm/debug.c:84 RSP: 0018:ffff880100000000 EFLAGS: 00010086 RAX: ffff8801d18497c0 RBX: ffffea0002d15800 RCX: ffffffff8148d2d0 RDX: 0000000000000000 RSI: ffffffff838a7e20 RDI: ffffea0002d15800 RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000002 R11: fffffbfff0ad581e R12: 0000000000000000 R13: ffffffff838a7e20 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: ffff8800fffffff8 CR3: 000000000420b000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: Call Trace: <UNK> Code: dd 06 00 e9 1d fd ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb 48 83 ec 08 <e8> 51 f8 ec ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89