random: sshd: uninitialized urandom read (32 bytes read, 126 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 ffff8801d3308338 by task syzkaller166828/3317 CPU: 1 PID: 3317 Comm: syzkaller166828 Not tainted 4.4.111-gc2f631b #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 9dd9d0249367bd41 ffff8801d157f8d0 ffffffff81d0513d ffffea00074cc200 ffff8801d3308338 0000000000000000 ffff8801d3308338 0000000000000000 ffff8801d157f908 ffffffff814fd433 ffff8801d3308338 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x73/0x260 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x285/0x370 mm/kasan/report.c:408 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] __lock_acquire+0x387e/0x4b50 kernel/locking/lockdep.c:3092 [] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline] [] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159 [] remove_wait_queue+0x14/0x40 kernel/sched/wait.c:49 [] ep_remove_wait_queue fs/eventpoll.c:530 [inline] [] ep_unregister_pollwait.isra.6+0xa8/0x220 fs/eventpoll.c:548 [] ep_free+0x93/0x1c0 fs/eventpoll.c:765 [] ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:797 [] __fput+0x233/0x6d0 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x104/0x180 kernel/task_work.c:115 [] exit_task_work include/linux/task_work.h:21 [inline] [] do_exit+0x871/0x2a20 kernel/exit.c:755 [] do_group_exit+0x108/0x320 kernel/exit.c:885 [] SYSC_exit_group kernel/exit.c:896 [inline] [] SyS_exit_group+0x1d/0x20 kernel/exit.c:894 [] entry_SYSCALL_64_fastpath+0x16/0x92 Allocated by task 3317: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [] kmem_cache_alloc_trace+0x100/0x2b0 mm/slub.c:2642 [] kmalloc include/linux/slab.h:476 [inline] [] kzalloc include/linux/slab.h:620 [inline] [] binder_get_thread+0x181/0x7a0 drivers/android/binder.c:4452 [] binder_poll+0x4a/0x210 drivers/android/binder.c:4555 [] ep_item_poll fs/eventpoll.c:806 [inline] [] ep_insert fs/eventpoll.c:1319 [inline] [] SYSC_epoll_ctl fs/eventpoll.c:1934 [inline] [] SyS_epoll_ctl+0x10b1/0x2050 fs/eventpoll.c:1833 [] entry_SYSCALL_64_fastpath+0x16/0x92 Freed by task 3317: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kfree+0xfc/0x300 mm/slub.c:3749 [] binder_free_thread drivers/android/binder.c:4480 [inline] [] binder_thread_dec_tmpref+0x1c1/0x250 drivers/android/binder.c:2036 [] binder_thread_release+0x27d/0x540 drivers/android/binder.c:4544 [] binder_ioctl+0xb94/0x12e0 drivers/android/binder.c:4760 [] vfs_ioctl fs/ioctl.c:43 [inline] [] do_vfs_ioctl+0x7aa/0xee0 fs/ioctl.c:607 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613 [] entry_SYSCALL_64_fastpath+0x16/0x92 The buggy address belongs to the object at ffff8801d3308280 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8801d3308280, ffff8801d3308480) The buggy address belongs to the page: audit: type=1400 audit(1516073161.441:5): avc: denied { use } for pid=3319 comm="init" path="/dev/console" dev="devtmpfs" ino=23 scontext=system_u:object_r:unlabeled_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=fd permissive=1 page:ffffea00074cc200 count:1 mapcount:-2146697203 mapping: (null) index:0x0 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 3168 Comm: rsyslogd Not tainted 4.4.111-gc2f631b #27 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d3475f00 task.stack: ffff8801d3670000 RIP: 0010:[] [] sk_can_busy_loop include/net/busy_poll.h:63 [inline] RIP: 0010:[] [] sock_poll+0x81/0x580 net/socket.c:1016 RSP: 0018:ffff8801d36777a0 EFLAGS: 00010203 RAX: dffffc0000000000 RBX: ffff8801cf541980 RCX: ffffffff82ded3fc RDX: 0000000000000034 RSI: ffff8801d3677960 RDI: 00000000000001a4 RBP: ffff8801d36777d8 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 1ffff1003a6ceeb2 R12: 0000000000000000 R13: ffff8800b6617800 R14: ffff8801d3677960 R15: 0000000000000001 FS: 00007f9474c45700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000796435b64f0 CR3: 00000001d210c000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff81578111 0000000000000000 ffff8800b6617800 0000000000000001 ffffffff82ded3e0 0000000000000000 0000000000000001 ffff8801d3677c28 ffffffff8155ccc7 ffffffff8155c355 0000000000000000 0000000000000000 Call Trace: [] do_select+0xa37/0x13f0 fs/select.c:460 [] core_sys_select+0x3d8/0x740 fs/select.c:599 [] SYSC_select fs/select.c:640 [inline] [] SyS_select+0x14a/0x1d0 fs/select.c:622 [] entry_SYSCALL_64_fastpath+0x16/0x92 Code: 48 c1 ea 03 80 3c 02 00 0f 85 a6 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 20 49 8d bc 24 a4 01 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 RIP [] sk_can_busy_loop include/net/busy_poll.h:63 [inline] RIP [] sock_poll+0x81/0x580 net/socket.c:1016 RSP ---[ end trace 9caeacb0a953a91d ]---