[ 16.656871] random: sshd: uninitialized urandom read (32 bytes read, 31 bits of entropy available) [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.985170] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 22.384692] random: sshd: uninitialized urandom read (32 bytes read, 36 bits of entropy available) [ 23.229352] random: sshd: uninitialized urandom read (32 bytes read, 97 bits of entropy available) [ 23.394028] random: sshd: uninitialized urandom read (32 bytes read, 103 bits of entropy available) Warning: Permanently added '10.128.15.224' (ECDSA) to the list of known hosts. [ 28.936443] random: sshd: uninitialized urandom read (32 bytes read, 109 bits of entropy available) executing program [ 29.034425] ================================================================== [ 29.041825] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 29.048460] Read of size 8 at addr ffff8801d32cd9b8 by task syzkaller036721/3315 [ 29.055967] [ 29.057572] CPU: 0 PID: 3315 Comm: syzkaller036721 Not tainted 4.4.112-g3fc4284 #25 [ 29.065331] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.074658] 0000000000000000 afb663302a72d215 ffff8801d0ae7850 ffffffff81d054ed [ 29.082635] ffffea00074cb300 ffff8801d32cd9b8 0000000000000000 ffff8801d32cd9b8 [ 29.091299] 0000000000000000 ffff8801d0ae7888 ffffffff814fd953 ffff8801d32cd9b8 [ 29.099272] Call Trace: [ 29.101831] [] dump_stack+0xc1/0x124 [ 29.107172] [] print_address_description+0x73/0x260 [ 29.113806] [] kasan_report+0x285/0x370 [ 29.120706] [] ? __lock_acquire+0x387e/0x4b50 [ 29.126824] [] __asan_report_load8_noabort+0x14/0x20 [ 29.133549] [] __lock_acquire+0x387e/0x4b50 [ 29.139491] [] ? __lock_acquire+0xb5f/0x4b50 [ 29.145955] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.153904] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 29.160722] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.167715] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.174708] [] lock_acquire+0x15e/0x460 [ 29.180304] [] ? remove_wait_queue+0x14/0x40 [ 29.186335] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.192625] [] ? remove_wait_queue+0x14/0x40 [ 29.198662] [] remove_wait_queue+0x14/0x40 [ 29.204526] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.212203] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.220319] [] ? ep_free+0x1c0/0x1c0 [ 29.227146] [] ep_free+0x93/0x1c0 [ 29.232221] [] ? ep_free+0x1c0/0x1c0 [ 29.238073] [] ep_eventpoll_release+0x44/0x60 [ 29.244191] [] __fput+0x233/0x6d0 [ 29.249270] [] ____fput+0x15/0x20 [ 29.254345] [] task_work_run+0x104/0x180 [ 29.260036] [] do_exit+0x871/0x2a20 [ 29.265290] [] ? handle_mm_fault+0x192d/0x3190 [ 29.273076] [] ? handle_mm_fault+0x3f2/0x3190 [ 29.279200] [] ? release_task+0x1240/0x1240 [ 29.285145] [] do_group_exit+0x108/0x320 [ 29.290834] [] SyS_exit_group+0x1d/0x20 [ 29.296432] [] ? do_group_exit+0x320/0x320 [ 29.304092] [] do_fast_syscall_32+0x314/0x890 [ 29.310212] [] sysenter_flags_fixed+0xd/0x17 [ 29.316237] [ 29.317835] Allocated by task 3315: [ 29.321434] [] save_stack_trace+0x26/0x50 [ 29.327326] [] save_stack+0x43/0xd0 [ 29.332952] [] kasan_kmalloc+0xad/0xe0 [ 29.338848] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.345432] [] binder_get_thread+0x181/0x7a0 [ 29.351588] [] binder_poll+0x4a/0x210 [ 29.357133] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.363124] [] do_fast_syscall_32+0x314/0x890 [ 29.369706] [] sysenter_flags_fixed+0xd/0x17 [ 29.375861] [ 29.377457] Freed by task 3315: [ 29.380704] [] save_stack_trace+0x26/0x50 [ 29.386599] [] save_stack+0x43/0xd0 [ 29.391964] [] kasan_slab_free+0x72/0xc0 [ 29.397771] [] kfree+0xfc/0x300 [ 29.402793] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.410892] [] binder_thread_release+0x27d/0x540 [ 29.417387] [] binder_ioctl+0xb94/0x12e0 [ 29.423200] [] compat_SyS_ioctl+0x28a/0x2540 [ 29.429342] [] do_fast_syscall_32+0x314/0x890 [ 29.435585] [] sysenter_flags_fixed+0xd/0x17 [ 29.441736] [ 29.443335] The buggy address belongs to the object at ffff8801d32cd900 [ 29.443335] which belongs to the cache kmalloc-512 of size 512 [ 29.456831] The buggy address is located 184 bytes inside of [ 29.456831] 512-byte region [ffff8801d32cd900, ffff8801d32cdb00) [ 29.468676] The buggy address belongs to the page: [ 30.927790] PANIC: double fault, error_code: 0x0 [ 30.932563] CPU: 0 PID: 3315 Comm: syzkaller036721 Not tainted 4.4.112-g3fc4284 #25 [ 30.940328] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.949659] task: ffff8801d219df00 task.stack: ffff8801d0ae0000 [ 30.955699] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 30.964552] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 30.969987] RAX: ffff8801d219df00 RBX: ffffea00074cb300 RCX: ffffffff8148fea0 [ 30.977236] RDX: 0000000000000000 RSI: ffffffff838a8620 RDI: ffffea00074cb300 [ 30.984487] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 30.991741] R10: 0000000000000002 R11: fffffbfff0ad7a1e R12: 0000000000000000 [ 30.998989] R13: ffffffff838a8620 R14: 0000000000000000 R15: 0000000000000000 [ 31.006230] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 31.014433] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 31.020295] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 31.027546] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.034791] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.042031] Stack: [ 31.044147] [ 31.046179] Call Trace: [ 31.048738] [ 31.050764] 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 11 01 ed ff 48 8d 7b 10 48 b8 00 00 00 00 00 fc ff df 48 89 [ 31.077679] Kernel panic - not syncing: Machine halted. [ 31.083022] CPU: 0 PID: 3315 Comm: syzkaller036721 Not tainted 4.4.112-g3fc4284 #25 [ 31.090791] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.100123] 0000000000000000 afb663302a72d215 ffff8801db20ce38 ffffffff81d054ed [ 31.108098] ffffffff83836a60 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 31.116069] 0000000000000000 ffff8801db20cf00 ffffffff81419dca 0000000041b58ab3 [ 31.124034] Call Trace: [ 31.126773] <#DF> [] dump_stack+0xc1/0x124 [ 31.133498] [] panic+0x1aa/0x388 [ 31.138753] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 31.146000] [] ? vprintk_emit+0x242/0x850 [ 31.152031] [] ? dump_page_badflags+0x2f/0x250 [ 31.158233] [] ? vprintk_emit+0x242/0x850 [ 31.164004] [] df_debug+0x2d/0x30 [ 31.169084] [] do_double_fault+0x10b/0x210 [ 31.174939] [] double_fault+0x2d/0x40 [ 31.180383] [] ? dump_page_badflags+0x180/0x250 [ 31.186681] [] ? dump_page_badflags+0x1a/0x250 [ 31.192898] <> [ 31.196645] Dumping ftrace buffer: [ 31.200454] (ftrace buffer empty) [ 31.204136] Kernel Offset: disabled [ 31.208393] Rebooting in 86400 seconds..