[ 15.351034] random: sshd: uninitialized urandom read (32 bytes read, 32 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: [ 20.174586] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.482877] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.387697] random: sshd: uninitialized urandom read (32 bytes read, 113 bits of entropy available) [ 21.557879] random: sshd: uninitialized urandom read (32 bytes read, 117 bits of entropy available) Warning: Permanently added '10.128.0.12' (ECDSA) to the list of known hosts. [ 26.921521] random: sshd: uninitialized urandom read (32 bytes read, 124 bits of entropy available) executing program [ 27.017859] ================================================================== [ 27.025255] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.031902] Read of size 8 at addr ffff8800b60cad38 by task syzkaller409497/3309 [ 27.039401] [ 27.040999] CPU: 1 PID: 3309 Comm: syzkaller409497 Not tainted 4.4.113-g202e079 #1 [ 27.048673] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.058001] 0000000000000000 9b31a6270000c463 ffff8801d0bc7870 ffffffff81d0278d [ 27.065982] ffffea0002d83280 ffff8800b60cad38 0000000000000000 ffff8800b60cad38 [ 27.074605] 0000000000000000 ffff8801d0bc78a8 ffffffff814fd053 ffff8800b60cad38 [ 27.082601] Call Trace: [ 27.085159] [] dump_stack+0xc1/0x124 [ 27.090498] [] print_address_description+0x73/0x260 [ 27.097132] [] kasan_report+0x285/0x370 [ 27.102726] [] ? __lock_acquire+0x387e/0x4b50 [ 27.108844] [] __asan_report_load8_noabort+0x14/0x20 [ 27.115568] [] __lock_acquire+0x387e/0x4b50 [ 27.121507] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.127537] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.134524] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.141346] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.148330] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.155314] [] lock_acquire+0x15e/0x460 [ 27.160917] [] ? remove_wait_queue+0x14/0x40 [ 27.166956] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.173252] [] ? remove_wait_queue+0x14/0x40 [ 27.179292] [] remove_wait_queue+0x14/0x40 [ 27.185156] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.192142] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.199385] [] ? ep_free+0x1c0/0x1c0 [ 27.204727] [] ep_free+0x93/0x1c0 [ 27.209802] [] ? ep_free+0x1c0/0x1c0 [ 27.215135] [] ep_eventpoll_release+0x44/0x60 [ 27.221252] [] __fput+0x233/0x6d0 [ 27.226322] [] ____fput+0x15/0x20 [ 27.231397] [] task_work_run+0x104/0x180 [ 27.237076] [] do_exit+0x82a/0x2a10 [ 27.242332] [] ? release_task+0x1240/0x1240 [ 27.248288] [] do_group_exit+0x108/0x320 [ 27.253973] [] SyS_exit_group+0x1d/0x20 [ 27.259568] [] ? do_group_exit+0x320/0x320 [ 27.265428] [] do_fast_syscall_32+0x314/0x890 [ 27.271565] [] sysenter_flags_fixed+0xd/0x17 [ 27.277591] [ 27.279190] Allocated by task 3309: [ 27.282783] [] save_stack_trace+0x26/0x50 [ 27.288667] [] save_stack+0x43/0xd0 [ 27.294051] [] kasan_kmalloc+0xad/0xe0 [ 27.299680] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.306259] [] binder_get_thread+0x15d/0x750 [ 27.312401] [] binder_poll+0x4a/0x210 [ 27.317936] [] SyS_epoll_ctl+0x10b1/0x2040 [ 27.323907] [] do_fast_syscall_32+0x314/0x890 [ 27.330149] [] sysenter_flags_fixed+0xd/0x17 [ 27.336298] [ 27.337897] Freed by task 3309: [ 27.341152] [] save_stack_trace+0x26/0x50 [ 27.347037] [] save_stack+0x43/0xd0 [ 27.352490] [] kasan_slab_free+0x72/0xc0 [ 27.358286] [] kfree+0xfc/0x300 [ 27.363317] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.370071] [] binder_thread_release+0x27d/0x540 [ 27.376563] [] binder_ioctl+0xb94/0x12e0 [ 27.382363] [] compat_SyS_ioctl+0x28a/0x2540 [ 27.388511] [] do_fast_syscall_32+0x314/0x890 [ 27.394741] [] sysenter_flags_fixed+0xd/0x17 [ 27.400896] [ 27.402498] The buggy address belongs to the object at ffff8800b60cac80 [ 27.402498] which belongs to the cache kmalloc-512 of size 512 [ 27.415128] The buggy address is located 184 bytes inside of [ 27.415128] 512-byte region [ffff8800b60cac80, ffff8800b60cae80) [ 27.427058] The buggy address belongs to the page: [ 28.958416] PANIC: double fault, error_code: 0x0 [ 28.963196] CPU: 1 PID: 3309 Comm: syzkaller409497 Not tainted 4.4.113-g202e079 #1 [ 28.970872] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.980198] task: ffff8801d1b3af80 task.stack: ffff8801d0bc0000 [ 28.986225] RIP: 0010:[] [] dump_page_badflags+0x8/0x250 [ 28.994993] RSP: 0018:ffff880100000000 EFLAGS: 00010046 [ 29.000421] RAX: ffff8801d1b3af80 RBX: ffffea0002d83280 RCX: ffffffff8148f8d0 [ 29.007669] RDX: 0000000000000000 RSI: ffffffff838a8de0 RDI: ffffea0002d83280 [ 29.014910] RBP: ffff880100000010 R08: 0000000000000001 R09: 0000000000000000 [ 29.022154] R10: 0000000000000002 R11: fffffbfff0ad7e26 R12: 0000000000000000 [ 29.029401] R13: ffffffff838a8de0 R14: 0000000000000000 R15: 0000000000000000 [ 29.036643] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.044839] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 29.050687] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.057931] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.065173] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.072418] Stack: [ 29.075095] [ 29.076695] Call Trace: [ 29.079245] [ 29.081288] Code: 00 e9 83 fd ff ff e8 78 df 06 00 e9 50 fd ff ff e8 6e df 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 b1 04 [ 29.108097] Kernel panic - not syncing: Machine halted. [ 29.113431] CPU: 1 PID: 3309 Comm: syzkaller409497 Not tainted 4.4.113-g202e079 #1 [ 29.121125] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.130446] 0000000000000000 9b31a6270000c463 ffff8801db30ce38 ffffffff81d0278d [ 29.138408] ffffffff83837200 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.146373] 0000000000000000 ffff8801db30cf00 ffffffff81419b6a 0000000041b58ab3 [ 29.154344] Call Trace: [ 29.156892] <#DF> [] dump_stack+0xc1/0x124 [ 29.162959] [] panic+0x1aa/0x388 [ 29.167954] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.174847] [] ? vprintk_emit+0x242/0x850 [ 29.180615] [] ? dump_page_badflags+0x1d/0x250 [ 29.186822] [] ? vprintk_emit+0x242/0x850 [ 29.192586] [] df_debug+0x2d/0x30 [ 29.197658] [] do_double_fault+0x10b/0x210 [ 29.203510] [] double_fault+0x2d/0x40 [ 29.208934] [] ? dump_page_badflags+0x180/0x250 [ 29.215220] [] ? dump_page_badflags+0x8/0x250 [ 29.221335] <> [ 29.224670] Dumping ftrace buffer: [ 29.228475] (ftrace buffer empty) [ 29.232162] Kernel Offset: disabled [ 29.235764] Rebooting in 86400 seconds..