[ 15.439055] random: sshd: uninitialized urandom read (32 bytes read, 32 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: [ 19.174456] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 19.555300] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.362097] random: sshd: uninitialized urandom read (32 bytes read, 94 bits of entropy available) [ 36.334193] random: sshd: uninitialized urandom read (32 bytes read, 106 bits of entropy available) Warning: Permanently added '10.128.15.231' (ECDSA) to the list of known hosts. [ 41.693775] random: sshd: uninitialized urandom read (32 bytes read, 110 bits of entropy available) executing program [ 41.787587] ================================================================== [ 41.794996] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 41.801638] Read of size 8 at addr ffff8801d08c1738 by task syzkaller339855/3331 [ 41.809140] [ 41.810739] CPU: 0 PID: 3331 Comm: syzkaller339855 Not tainted 4.4.111-g1849cd3 #19 [ 41.818501] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 41.827837] 0000000000000000 b2ad5034e8ade1ea ffff8801d0c4f850 ffffffff81d0509d [ 41.835810] ffffea0007423000 ffff8801d08c1738 0000000000000000 ffff8801d08c1738 [ 41.843789] 0000000000000000 ffff8801d0c4f888 ffffffff814fd433 ffff8801d08c1738 [ 41.851755] Call Trace: [ 41.854315] [] dump_stack+0xc1/0x124 [ 41.859663] [] print_address_description+0x73/0x260 [ 41.866296] [] kasan_report+0x285/0x370 [ 41.871889] [] ? __lock_acquire+0x387e/0x4b50 [ 41.878003] [] __asan_report_load8_noabort+0x14/0x20 [ 41.884724] [] __lock_acquire+0x387e/0x4b50 [ 41.890664] [] ? __lock_acquire+0xb5f/0x4b50 [ 41.896690] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.903670] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 41.910476] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.917467] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 41.924449] [] lock_acquire+0x15e/0x460 [ 41.930041] [] ? remove_wait_queue+0x14/0x40 [ 41.936066] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 41.942353] [] ? remove_wait_queue+0x14/0x40 [ 41.948902] [] remove_wait_queue+0x14/0x40 [ 41.954759] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 41.961743] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 41.968985] [] ? ep_free+0x1c0/0x1c0 [ 41.974316] [] ep_free+0x93/0x1c0 [ 41.979402] [] ? ep_free+0x1c0/0x1c0 [ 41.984744] [] ep_eventpoll_release+0x44/0x60 [ 41.990864] [] __fput+0x233/0x6d0 [ 41.995950] [] ____fput+0x15/0x20 [ 42.001046] [] task_work_run+0x104/0x180 [ 42.006732] [] do_exit+0x871/0x2a20 [ 42.011978] [] ? handle_mm_fault+0x192d/0x3190 [ 42.018188] [] ? handle_mm_fault+0x3f2/0x3190 [ 42.024306] [] ? release_task+0x1240/0x1240 [ 42.030247] [] do_group_exit+0x108/0x320 [ 42.035936] [] SyS_exit_group+0x1d/0x20 [ 42.041530] [] ? do_group_exit+0x320/0x320 [ 42.047384] [] do_fast_syscall_32+0x314/0x890 [ 42.053498] [] sysenter_flags_fixed+0xd/0x17 [ 42.059519] [ 42.061118] Allocated by task 3331: [ 42.064709] [] save_stack_trace+0x26/0x50 [ 42.070593] [] save_stack+0x43/0xd0 [ 42.075969] [] kasan_kmalloc+0xad/0xe0 [ 42.081591] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 42.088181] [] binder_get_thread+0x181/0x7a0 [ 42.094339] [] binder_poll+0x4a/0x210 [ 42.099880] [] SyS_epoll_ctl+0x10b1/0x2050 [ 42.105852] [] do_fast_syscall_32+0x314/0x890 [ 42.112083] [] sysenter_flags_fixed+0xd/0x17 [ 42.118225] [ 42.119823] Freed by task 3331: [ 42.123066] [] save_stack_trace+0x26/0x50 [ 42.128949] [] save_stack+0x43/0xd0 [ 42.134312] [] kasan_slab_free+0x72/0xc0 [ 42.140103] [] kfree+0xfc/0x300 [ 42.145127] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 42.151876] [] binder_thread_release+0x27d/0x540 [ 42.158363] [] binder_ioctl+0xb94/0x12e0 [ 42.164161] [] compat_SyS_ioctl+0x28a/0x2540 [ 42.170321] [] do_fast_syscall_32+0x314/0x890 [ 42.176560] [] sysenter_flags_fixed+0xd/0x17 [ 42.182710] [ 42.184307] The buggy address belongs to the object at ffff8801d08c1680 [ 42.184307] which belongs to the cache kmalloc-512 of size 512 [ 42.196932] The buggy address is located 184 bytes inside of [ 42.196932] 512-byte region [ffff8801d08c1680, ffff8801d08c1880) [ 42.209490] The buggy address belongs to the page: [ 43.778442] PANIC: double fault, error_code: 0x0 [ 43.783232] CPU: 0 PID: 0 Comm: Not tainted 4.4.111-g1849cd3 #19 [ 43.789434] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.798761] task: ffff8801d091c740 task.stack: ffffea0007423000 [ 43.804797] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 43.813683] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 43.819101] RAX: ffff8801d091c740 RBX: ffffea0007423000 RCX: ffffffff8148f980 [ 43.826343] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0007423000 [ 43.833598] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 43.840854] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 43.848105] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 43.855360] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 43.863558] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 43.869424] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 43.876666] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 43.883909] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 43.891151] Stack: [ 43.893267] [ 43.894864] Call Trace: [ 43.897416] [ 43.899444] 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 [ 43.926375] Kernel panic - not syncing: Machine halted. [ 43.931716] CPU: 0 PID: 0 Comm: Not tainted 4.4.111-g1849cd3 #19 [ 43.937916] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.947244] 0000000000000000 b2ad5034e8ade1ea ffff8801db20ce38 ffffffff81d0509d [ 43.955215] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 43.963185] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 43.971145] Call Trace: [ 43.973703] <#DF> [] dump_stack+0xc1/0x124 [ 43.979866] [] panic+0x1aa/0x388 [ 43.984859] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 43.991758] [] ? vprintk_emit+0x242/0x850 [ 43.997528] [] ? dump_page_badflags+0x2f/0x250 [ 44.003729] [] ? vprintk_emit+0x242/0x850 [ 44.009509] [] df_debug+0x2d/0x30 [ 44.014585] [] do_double_fault+0x10b/0x210 [ 44.020441] [] double_fault+0x2d/0x40 [ 44.025874] [] ? dump_page_badflags+0x180/0x250 [ 44.032176] [] ? dump_page_badflags+0x1a/0x250 [ 44.038382] <> [ 44.041961] Dumping ftrace buffer: [ 44.045908] (ftrace buffer empty) [ 44.049590] Kernel Offset: disabled [ 44.053210] Rebooting in 86400 seconds..