[ 16.732513] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.844448] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 21.178314] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 21.997852] random: sshd: uninitialized urandom read (32 bytes read, 98 bits of entropy available) [ 22.175559] random: sshd: uninitialized urandom read (32 bytes read, 103 bits of entropy available) Warning: Permanently added '10.128.15.228' (ECDSA) to the list of known hosts. [ 27.626594] random: sshd: uninitialized urandom read (32 bytes read, 109 bits of entropy available) executing program [ 27.732797] ================================================================== [ 27.740195] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.746871] Read of size 8 at addr ffff8800b4af9238 by task syzkaller112102/3327 [ 27.754373] [ 27.755988] CPU: 1 PID: 3327 Comm: syzkaller112102 Not tainted 4.4.111-g7902639 #18 [ 27.763744] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.773078] 0000000000000000 e6f40be999d8d73d ffff8801d045f850 ffffffff81d0509d [ 27.781388] ffffea0002d2be00 ffff8800b4af9238 0000000000000000 ffff8800b4af9238 [ 27.790298] 0000000000000000 ffff8801d045f888 ffffffff814fd433 ffff8800b4af9238 [ 27.798519] Call Trace: [ 27.801078] [] dump_stack+0xc1/0x124 [ 27.806413] [] print_address_description+0x73/0x260 [ 27.813054] [] kasan_report+0x285/0x370 [ 27.818654] [] ? __lock_acquire+0x387e/0x4b50 [ 27.824762] [] __asan_report_load8_noabort+0x14/0x20 [ 27.831748] [] __lock_acquire+0x387e/0x4b50 [ 27.837696] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.843743] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.850737] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.857563] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.864663] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.871662] [] lock_acquire+0x15e/0x460 [ 27.877280] [] ? remove_wait_queue+0x14/0x40 [ 27.883319] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.889619] [] ? remove_wait_queue+0x14/0x40 [ 27.895658] [] remove_wait_queue+0x14/0x40 [ 27.901526] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.908529] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.915787] [] ? ep_free+0x1c0/0x1c0 [ 27.921143] [] ep_free+0x93/0x1c0 [ 27.926236] [] ? ep_free+0x1c0/0x1c0 [ 27.931597] [] ep_eventpoll_release+0x44/0x60 [ 27.937732] [] __fput+0x233/0x6d0 [ 27.942821] [] ____fput+0x15/0x20 [ 27.947912] [] task_work_run+0x104/0x180 [ 27.953608] [] do_exit+0x871/0x2a20 [ 27.958868] [] ? handle_mm_fault+0x192d/0x3190 [ 27.965093] [] ? handle_mm_fault+0x3f2/0x3190 [ 27.971218] [] ? release_task+0x1240/0x1240 [ 27.977171] [] do_group_exit+0x108/0x320 [ 27.982862] [] SyS_exit_group+0x1d/0x20 [ 27.988469] [] ? do_group_exit+0x320/0x320 [ 27.994333] [] do_fast_syscall_32+0x314/0x890 [ 28.000464] [] sysenter_flags_fixed+0xd/0x17 [ 28.006510] [ 28.008120] Allocated by task 3327: [ 28.011718] [] save_stack_trace+0x26/0x50 [ 28.017610] [] save_stack+0x43/0xd0 [ 28.022985] [] kasan_kmalloc+0xad/0xe0 [ 28.028644] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 28.035241] [] binder_get_thread+0x181/0x7a0 [ 28.041393] [] binder_poll+0x4a/0x210 [ 28.046940] [] SyS_epoll_ctl+0x10b1/0x2050 [ 28.052931] [] do_fast_syscall_32+0x314/0x890 [ 28.059185] [] sysenter_flags_fixed+0xd/0x17 [ 28.065362] [ 28.066963] Freed by task 3327: [ 28.070209] [] save_stack_trace+0x26/0x50 [ 28.076103] [] save_stack+0x43/0xd0 [ 28.081479] [] kasan_slab_free+0x72/0xc0 [ 28.087291] [] kfree+0xfc/0x300 [ 28.092319] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.099087] [] binder_thread_release+0x27d/0x540 [ 28.105590] [] binder_ioctl+0xb94/0x12e0 [ 28.111402] [] compat_SyS_ioctl+0x28a/0x2540 [ 28.117572] [] do_fast_syscall_32+0x314/0x890 [ 28.123823] [] sysenter_flags_fixed+0xd/0x17 [ 28.129983] [ 28.131594] The buggy address belongs to the object at ffff8800b4af9180 [ 28.131594] which belongs to the cache kmalloc-512 of size 512 [ 28.144231] The buggy address is located 184 bytes inside of [ 28.144231] 512-byte region [ffff8800b4af9180, ffff8800b4af9380) [ 28.156094] The buggy address belongs to the page: [ 29.694081] PANIC: double fault, error_code: 0x0 [ 29.698953] CPU: 1 PID: 3327 Comm: syzkaller112102 Not tainted 4.4.111-g7902639 #18 [ 29.707158] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.716477] task: ffff8801d15e2f80 task.stack: ffff8801d0458000 [ 29.722496] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 29.731355] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 29.736780] RAX: ffff8801d15e2f80 RBX: ffffea0002d2be00 RCX: ffffffff8148f980 [ 29.744033] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0002d2be00 [ 29.751285] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 29.758530] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 29.765780] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 29.773021] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.781223] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 29.787085] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.794349] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.801592] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.808826] Stack: [ 29.810936] [ 29.812527] Call Trace: [ 29.815081] [ 29.817111] Code: e2 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 61 06 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 29.844258] Kernel panic - not syncing: Machine halted. [ 29.849588] CPU: 1 PID: 3327 Comm: syzkaller112102 Not tainted 4.4.111-g7902639 #18 [ 29.857343] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.866662] 0000000000000000 e6f40be999d8d73d ffff8801db30ce38 ffffffff81d0509d [ 29.874604] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.882583] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 29.891241] Call Trace: [ 29.893788] <#DF> [] dump_stack+0xc1/0x124 [ 29.899848] [] panic+0x1aa/0x388 [ 29.904826] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.911725] [] ? vprintk_emit+0x242/0x850 [ 29.917492] [] ? dump_page_badflags+0x2f/0x250 [ 29.923685] [] ? vprintk_emit+0x242/0x850 [ 29.929450] [] df_debug+0x2d/0x30 [ 29.934519] [] do_double_fault+0x10b/0x210 [ 29.940369] [] double_fault+0x2d/0x40 [ 29.945783] [] ? dump_page_badflags+0x180/0x250 [ 29.952065] [] ? dump_page_badflags+0x1a/0x250 [ 29.958262] <> [ 29.961654] Dumping ftrace buffer: [ 29.965447] (ftrace buffer empty) [ 29.969131] Kernel Offset: disabled [ 29.972723] Rebooting in 86400 seconds..