random: sshd: uninitialized urandom read (32 bytes read, 125 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 ffff8801d27179b8 by task syzkaller970106/3325 CPU: 0 PID: 3325 Comm: syzkaller970106 Not tainted 4.4.111-gc2f631b #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 568079f835e377ba ffff8800b40d7850 ffffffff81d0513d ffffea000749c580 ffff8801d27179b8 0000000000000000 ffff8801d27179b8 0000000000000000 ffff8800b40d7888 ffffffff814fd433 ffff8801d27179b8 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 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Allocated by task 3325: [] 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 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 Freed by task 3325: [] 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 [] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [] compat_SyS_ioctl+0x28a/0x2540 fs/compat_ioctl.c:1544 [] do_syscall_32_irqs_on arch/x86/entry/common.c:390 [inline] [] do_fast_syscall_32+0x314/0x890 arch/x86/entry/common.c:457 [] sysenter_flags_fixed+0xd/0x17 The buggy address belongs to the object at ffff8801d2717900 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 184 bytes inside of 512-byte region [ffff8801d2717900, ffff8801d2717b00) The buggy address belongs to the page: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.111-gc2f631b #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801da3a97c0 task.stack: ffff8801da3b8000 RIP: 0010:[] [] skb_get include/linux/skbuff.h:1201 [inline] RIP: 0010:[] [] skb_clone_fraglist net/core/skbuff.c:561 [inline] RIP: 0010:[] [] __pskb_copy_fclone+0x49c/0xc10 net/core/skbuff.c:1094 RSP: 0018:ffff8801db307978 EFLAGS: 00010206 RAX: ffff8801da3a97c0 RBX: ffff8800b4bc4280 RCX: ffffffff82e10b7c RDX: 0000000000000100 RSI: ffff8800b49540c8 RDI: ffff8801d0803448 RBP: ffff8801db3079e8 R08: ffffed003a100659 R09: ffffed003a100659 R10: 0000000000000007 R11: ffffed003a100658 R12: 8000000000004080 R13: dffffc0000000000 R14: 0000000000000500 R15: ffff8800b4954000 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a5e68b9100 CR3: 00000000b9b1e000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff88021fffd048 ffff8801d2868000 ffff8800b4954030 dffffc0000000000 0000000000000001 ffff8800b4954000 ffff880100000000 ffffffff02080020 ffff8800b49540c8 ffff8801d2868000 ffff8800b11cd340 ffff8800b11ccc80 Call Trace: [] __pskb_copy include/linux/skbuff.h:874 [inline] [] pskb_copy include/linux/skbuff.h:2540 [inline] [] tcp_transmit_skb+0x1cb1/0x2ce0 net/ipv4/tcp_output.c:923 [] __tcp_retransmit_skb+0x47f/0x17b0 net/ipv4/tcp_output.c:2647 [] tcp_retransmit_skb+0x23/0x2c0 net/ipv4/tcp_output.c:2664 [] tcp_retransmit_timer+0xa60/0x1f10 net/ipv4/tcp_timer.c:446 [] tcp_write_timer_handler+0x21e/0x6d0 net/ipv4/tcp_timer.c:528 [] tcp_write_timer+0xa1/0xd0 net/ipv4/tcp_timer.c:546 [] call_timer_fn+0x18b/0x860 kernel/time/timer.c:1178 [] __run_timers kernel/time/timer.c:1254 [inline] [] run_timer_softirq+0x604/0xbb0 kernel/time/timer.c:1437 [] __do_softirq+0x24d/0xa59 kernel/softirq.c:273 [] invoke_softirq kernel/softirq.c:350 [inline] [] irq_exit+0x119/0x140 kernel/softirq.c:391 [] exiting_irq arch/x86/include/asm/apic.h:653 [inline] [] smp_apic_timer_interrupt+0x7b/0xa0 arch/x86/kernel/apic/apic.c:926 [] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:725 [] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline] [] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:291 [] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:282 [] default_idle_call+0x48/0x70 kernel/sched/idle.c:93 [] cpuidle_idle_call kernel/sched/idle.c:157 [inline] [] cpu_idle_loop kernel/sched/idle.c:253 [inline] [] cpu_startup_entry+0x605/0x820 kernel/sched/idle.c:301 [] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 Code: 08 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 39 07 00 00 4d 8b 64 24 08 4d 85 e4 74 33 49 bd 00 00 00 00 00 fc ff df e8 04 f3 54 fe 41 ff 84 24 dc 00 00 00 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 RIP [] skb_get include/linux/skbuff.h:1201 [inline] RIP [] skb_clone_fraglist net/core/skbuff.c:561 [inline] RIP [] __pskb_copy_fclone+0x49c/0xc10 net/core/skbuff.c:1094 RSP ---[ end trace 78e98d7b9167754e ]---