[ 16.248965] 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: [ 22.169641] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 22.467371] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 23.352262] random: sshd: uninitialized urandom read (32 bytes read, 108 bits of entropy available) [ 23.545500] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) Warning: Permanently added '10.128.15.218' (ECDSA) to the list of known hosts. [ 28.963658] random: sshd: uninitialized urandom read (32 bytes read, 122 bits of entropy available) executing program [ 29.060307] ================================================================== [ 29.067717] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 29.074355] Read of size 8 at addr ffff8800b46d6d38 by task syzkaller593600/3326 [ 29.081852] [ 29.083451] CPU: 0 PID: 3326 Comm: syzkaller593600 Not tainted 4.4.110-g618a510 #22 [ 29.091220] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.100548] 0000000000000000 932588a676e06a35 ffff8801cfca78d0 ffffffff81d04e3d [ 29.108511] ffffea0002d1b580 ffff8800b46d6d38 0000000000000000 ffff8800b46d6d38 [ 29.116470] 0000000000000000 ffff8801cfca7908 ffffffff814fd1f3 ffff8800b46d6d38 [ 29.124447] Call Trace: [ 29.127011] [] dump_stack+0xc1/0x124 [ 29.132350] [] print_address_description+0x73/0x260 [ 29.138982] [] kasan_report+0x285/0x370 [ 29.144582] [] ? __lock_acquire+0x387e/0x4b50 [ 29.150705] [] __asan_report_load8_noabort+0x14/0x20 [ 29.157443] [] __lock_acquire+0x387e/0x4b50 [ 29.163381] [] ? __lock_acquire+0xb5f/0x4b50 [ 29.169407] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.176389] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 29.183369] [] ? mark_held_locks+0xaf/0x100 [ 29.189307] [] lock_acquire+0x15e/0x460 [ 29.194897] [] ? remove_wait_queue+0x14/0x40 [ 29.200924] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 29.207220] [] ? remove_wait_queue+0x14/0x40 [ 29.213246] [] remove_wait_queue+0x14/0x40 [ 29.219104] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 29.226099] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 29.233348] [] ? ep_free+0x1c0/0x1c0 [ 29.238685] [] ep_free+0x93/0x1c0 [ 29.243757] [] ? ep_free+0x1c0/0x1c0 [ 29.249090] [] ep_eventpoll_release+0x44/0x60 [ 29.255207] [] __fput+0x233/0x6d0 [ 29.260297] [] ____fput+0x15/0x20 [ 29.265370] [] task_work_run+0x104/0x180 [ 29.271061] [] do_exit+0x871/0x2a20 [ 29.276304] [] ? release_task+0x1240/0x1240 [ 29.282248] [] ? SyS_epoll_create+0x190/0x190 [ 29.288359] [] do_group_exit+0x108/0x320 [ 29.294042] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 29.300502] [] SyS_exit_group+0x1d/0x20 [ 29.306100] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.312642] [ 29.314245] Allocated by task 3326: [ 29.317836] [] save_stack_trace+0x26/0x50 [ 29.323721] [] save_stack+0x43/0xd0 [ 29.329082] [] kasan_kmalloc+0xad/0xe0 [ 29.334701] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 29.341273] [] binder_get_thread+0x181/0x7a0 [ 29.347420] [] binder_poll+0x4a/0x210 [ 29.352962] [] SyS_epoll_ctl+0x10b1/0x2050 [ 29.358930] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.365592] [ 29.367186] Freed by task 3326: [ 29.370429] [] save_stack_trace+0x26/0x50 [ 29.376317] [] save_stack+0x43/0xd0 [ 29.381679] [] kasan_slab_free+0x72/0xc0 [ 29.387469] [] kfree+0xfc/0x300 [ 29.392480] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 29.399231] [] binder_thread_release+0x27d/0x540 [ 29.405713] [] binder_ioctl+0xb94/0x12e0 [ 29.411520] [] do_vfs_ioctl+0x7aa/0xee0 [ 29.417249] [] SyS_ioctl+0x8f/0xc0 [ 29.422516] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 29.429186] [ 29.430785] The buggy address belongs to the object at ffff8800b46d6c80 [ 29.430785] which belongs to the cache kmalloc-512 of size 512 [ 29.443405] The buggy address is located 184 bytes inside of [ 29.443405] 512-byte region [ffff8800b46d6c80, ffff8800b46d6e80) [ 29.455253] The buggy address belongs to the page: [ 30.978937] PANIC: double fault, error_code: 0x0 [ 30.983730] CPU: 0 PID: 3326 Comm: syzkaller593600 Not tainted 4.4.110-g618a510 #22 [ 30.991490] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.000813] task: ffff8800b4db4740 task.stack: ffff8801cfca0000 [ 31.006835] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 31.015672] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 31.021087] RAX: ffff8800b4db4740 RBX: ffffea0002d1b580 RCX: ffffffff8148f740 [ 31.028330] RDX: 0000000000000000 RSI: ffffffff838a8320 RDI: ffffea0002d1b580 [ 31.035568] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 31.042805] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 31.050049] R13: ffffffff838a8320 R14: 0000000000000000 R15: 0000000000000000 [ 31.057285] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 31.065489] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 31.071336] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 31.078577] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.085826] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.093066] Stack: [ 31.095179] [ 31.096772] Call Trace: [ 31.099331] [ 31.101357] 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 [ 31.128018] Kernel panic - not syncing: Machine halted. [ 31.133365] CPU: 0 PID: 3326 Comm: syzkaller593600 Not tainted 4.4.110-g618a510 #22 [ 31.141123] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.150443] 0000000000000000 932588a676e06a35 ffff8801db20ce38 ffffffff81d04e3d [ 31.158397] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 31.166354] 0000000000000000 ffff8801db20cf00 ffffffff814197fa 0000000041b58ab3 [ 31.174304] Call Trace: [ 31.176853] <#DF> [] dump_stack+0xc1/0x124 [ 31.182923] [] panic+0x1aa/0x388 [ 31.187911] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 31.194805] [] ? vprintk_emit+0x242/0x850 [ 31.200571] [] ? dump_page_badflags+0x2f/0x250 [ 31.206768] [] ? vprintk_emit+0x242/0x850 [ 31.212533] [] df_debug+0x2d/0x30 [ 31.217603] [] do_double_fault+0x10b/0x210 [ 31.223456] [] double_fault+0x2d/0x40 [ 31.228886] [] ? dump_page_badflags+0x180/0x250 [ 31.235170] [] ? dump_page_badflags+0x1a/0x250 [ 31.241371] <> [ 31.244719] Dumping ftrace buffer: [ 31.248518] (ftrace buffer empty) [ 31.252202] Kernel Offset: disabled [ 31.255793] Rebooting in 86400 seconds..