[ 17.226655] random: sshd: uninitialized urandom read (32 bytes read, 33 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: [ 20.232542] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 20.581246] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.560702] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) [ 21.752137] random: sshd: uninitialized urandom read (32 bytes read, 120 bits of entropy available) Warning: Permanently added '10.128.15.212' (ECDSA) to the list of known hosts. [ 27.128811] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) executing program [ 27.233085] ================================================================== [ 27.240504] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.247151] Read of size 8 at addr ffff8801d3308338 by task syzkaller166828/3317 [ 27.254651] [ 27.256247] CPU: 1 PID: 3317 Comm: syzkaller166828 Not tainted 4.4.111-gc2f631b #27 [ 27.264015] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.273339] 0000000000000000 9dd9d0249367bd41 ffff8801d157f8d0 ffffffff81d0513d [ 27.281315] ffffea00074cc200 ffff8801d3308338 0000000000000000 ffff8801d3308338 [ 27.289274] 0000000000000000 ffff8801d157f908 ffffffff814fd433 ffff8801d3308338 [ 27.297227] Call Trace: [ 27.299789] [] dump_stack+0xc1/0x124 [ 27.305125] [] print_address_description+0x73/0x260 [ 27.311765] [] kasan_report+0x285/0x370 [ 27.317356] [] ? __lock_acquire+0x387e/0x4b50 [ 27.323470] [] __asan_report_load8_noabort+0x14/0x20 [ 27.330190] [] __lock_acquire+0x387e/0x4b50 [ 27.336126] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.342165] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.349146] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.356132] [] ? mark_held_locks+0xaf/0x100 [ 27.362072] [] lock_acquire+0x15e/0x460 [ 27.367663] [] ? remove_wait_queue+0x14/0x40 [ 27.373687] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.379975] [] ? remove_wait_queue+0x14/0x40 [ 27.385999] [] remove_wait_queue+0x14/0x40 [ 27.391861] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.398843] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.406084] [] ? ep_free+0x1c0/0x1c0 [ 27.411427] [] ep_free+0x93/0x1c0 [ 27.416514] [] ? ep_free+0x1c0/0x1c0 [ 27.421873] [] ep_eventpoll_release+0x44/0x60 [ 27.428013] [] __fput+0x233/0x6d0 [ 27.433129] [] ____fput+0x15/0x20 [ 27.433140] [] task_work_run+0x104/0x180 [ 27.433148] [] do_exit+0x871/0x2a20 [ 27.433154] [] ? release_task+0x1240/0x1240 [ 27.433165] [] ? SyS_epoll_create+0x190/0x190 [ 27.433178] [] ? fd_install+0x4d/0x60 [ 27.433183] [] do_group_exit+0x108/0x320 [ 27.433192] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.433197] [] SyS_exit_group+0x1d/0x20 [ 27.433206] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.433209] [ 27.433213] Allocated by task 3317: [ 27.433225] [] save_stack_trace+0x26/0x50 [ 27.433236] [] save_stack+0x43/0xd0 [ 27.433243] [] kasan_kmalloc+0xad/0xe0 [ 27.433251] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.433261] [] binder_get_thread+0x181/0x7a0 [ 27.433267] [] binder_poll+0x4a/0x210 [ 27.433274] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.433280] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.433281] [ 27.433283] Freed by task 3317: [ 27.433290] [] save_stack_trace+0x26/0x50 [ 27.433296] [] save_stack+0x43/0xd0 [ 27.433302] [] kasan_slab_free+0x72/0xc0 [ 27.433308] [] kfree+0xfc/0x300 [ 27.433315] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.433321] [] binder_thread_release+0x27d/0x540 [ 27.433328] [] binder_ioctl+0xb94/0x12e0 [ 27.433335] [] do_vfs_ioctl+0x7aa/0xee0 [ 27.433341] [] SyS_ioctl+0x8f/0xc0 [ 27.433347] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.433348] [ 27.433352] The buggy address belongs to the object at ffff8801d3308280 [ 27.433352] which belongs to the cache kmalloc-512 of size 512 [ 27.433357] The buggy address is located 184 bytes inside of [ 27.433357] 512-byte region [ffff8801d3308280, ffff8801d3308480) [ 27.433359] The buggy address belongs to the page: [ 27.649026] audit: type=1400 audit(1516073161.441:5): avc: denied { use } for pid=3319 comm="init" path="/dev/console" dev="devtmpfs" ino=23 scontext=system_u:object_r:unlabeled_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=fd permissive=1 [ 27.671187] page:ffffea00074cc200 count:1 mapcount:-2146697203 mapping: (null) index:0x0 [ 27.671369] kasan: CONFIG_KASAN_INLINE enabled [ 27.671376] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 27.671381] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 27.671387] Dumping ftrace buffer: [ 27.671391] (ftrace buffer empty) [ 27.671402] Modules linked in: [ 27.671409] CPU: 0 PID: 3168 Comm: rsyslogd Not tainted 4.4.111-gc2f631b #27 [ 27.671413] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.671416] task: ffff8801d3475f00 task.stack: ffff8801d3670000 [ 27.671433] RIP: 0010:[] [] sock_poll+0x81/0x580 [ 27.671437] RSP: 0018:ffff8801d36777a0 EFLAGS: 00010203 [ 27.671440] RAX: dffffc0000000000 RBX: ffff8801cf541980 RCX: ffffffff82ded3fc [ 27.671444] RDX: 0000000000000034 RSI: ffff8801d3677960 RDI: 00000000000001a4 [ 27.671447] RBP: ffff8801d36777d8 R08: 0000000000000001 R09: 0000000000000001 [ 27.671450] R10: 0000000000000000 R11: 1ffff1003a6ceeb2 R12: 0000000000000000 [ 27.671454] R13: ffff8800b6617800 R14: ffff8801d3677960 R15: 0000000000000001 [ 27.671459] FS: 00007f9474c45700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 27.671463] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.671466] CR2: 00000796435b64f0 CR3: 00000001d210c000 CR4: 0000000000160670 [ 27.671472] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 27.671475] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 27.671478] Stack: [ 27.671486] ffffffff81578111 0000000000000000 ffff8800b6617800 0000000000000001 [ 27.671492] ffffffff82ded3e0 0000000000000000 0000000000000001 ffff8801d3677c28 [ 27.671499] ffffffff8155ccc7 ffffffff8155c355 0000000000000000 0000000000000000 [ 27.671501] Call Trace: [ 27.671511] [] ? __fget_light+0xa1/0x1e0 [ 27.671518] [] ? sock_unregister+0x90/0x90 [ 27.671526] [] do_select+0xa37/0x13f0 [ 27.671531] [] ? do_select+0xc5/0x13f0 [ 27.671538] [] ? poll_select_set_timeout+0x110/0x110 [ 27.671547] [] ? __lock_is_held+0xa1/0xf0 [ 27.671552] [] ? __lock_is_held+0xa1/0xf0 [ 27.671558] [] ? set_fd_set.part.0+0x60/0x60 [ 27.671564] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.671571] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.671577] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.671583] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.671591] [] ? _raw_spin_unlock_irqrestore+0x45/0x70 [ 27.671600] [] ? __might_fault+0xe4/0x1d0 [ 27.671610] [] ? check_stack_object+0x68/0x140 [ 27.671616] [] ? __check_object_size+0x154/0x35b [ 27.671623] [] core_sys_select+0x3d8/0x740 [ 27.671628] [] ? core_sys_select+0xa2/0x740 [ 27.671634] [] ? do_select+0x13f0/0x13f0 [ 27.671640] [] ? __fget+0x232/0x3b0 [ 27.671645] [] ? __fget+0x47/0x3b0 [ 27.671651] [] ? __fdget+0x18/0x20 [ 27.671657] [] ? fput+0x20/0x150 [ 27.671663] [] ? SyS_sendmmsg+0x60/0x60 [ 27.671669] [] SyS_select+0x14a/0x1d0 [ 27.671675] [] ? core_sys_select+0x740/0x740 [ 27.671681] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.671688] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.671695] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.671781] Code: 48 c1 ea 03 80 3c 02 00 0f 85 a6 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 20 49 8d bc 24 a4 01 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 [ 27.671787] RIP [] sock_poll+0x81/0x580 [ 27.671789] RSP [ 27.671795] ---[ end trace 9caeacb0a953a91d ]--- [ 27.671799] Kernel panic - not syncing: Fatal exception [ 28.056411] flags: 0xffff8801d0fff639(locked|uptodate|dirty|lru|arch_1|reserved|private_2|writeback|head|swapcache|mappedtodisk|reclaim|swapbacked|unevictable|mlocked|uncached|compound_lock) [ 28.075598] page dumped because: VM_BUG_ON_PAGE(PageSlab(page)) [ 28.081649] ------------[ cut here ]------------ [ 28.086374] kernel BUG at include/linux/mm.h:460! [ 28.091185] invalid opcode: 0000 [#2] PREEMPT SMP KASAN [ 28.096985] Dumping ftrace buffer: [ 28.100497] (ftrace buffer empty) [ 28.104180] Modules linked in: [ 28.107465] CPU: 1 PID: 3317 Comm: syzkaller166828 Tainted: G D 4.4.111-gc2f631b #27 [ 28.116443] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.125770] task: ffff8800b524c740 task.stack: ffff8801d1578000 [ 28.131806] RIP: 0010:[] [] dump_page_badflags+0x191/0x250 [ 28.140748] RSP: 0018:ffff8801b592e6c0 EFLAGS: 00010086 [ 28.146166] RAX: ffff8800b524c740 RBX: ffffea00074cc200 RCX: ffffffff8148f96c [ 28.153407] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8800b524cfac [ 28.160662] RBP: ffff8801b592e6f0 R08: 0000000000000001 R09: 0000000000000000 [ 28.167905] R10: 0000000000000002 R11: fffffbfff0ad7820 R12: 0000000000000000 [ 28.175143] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 28.182386] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 28.190593] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 28.196446] CR2: 000000000043e570 CR3: 000000000420c000 CR4: 0000000000160670 [ 28.203689] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.210928] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.218167] Stack: [ 28.220286] 0000000000000000 ffffea00074cc200 0000000000000000 ffffffff838a8360 [ 28.228260] 0000000000000000 0000000000000000 ffff8801b592e730 ffffffff8148f991 [ 28.236237] 0000000000000000 ffffea00074cc200 0000000000000000 ffffffff838a8360 [ 28.244226] Call Trace: [ 28.246786] [ 28.248816] Code: 46 e8 14 05 ed ff 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 00 05 ed ff 31 d2 48 c7 c6 60 83 8a 83 48 89 df e8 6f fe ff ff <0f> 0b e8 d8 e0 06 00 e9 21 ff ff ff 89 4d d4 e8 cb e0 06 00 8b [ 28.275769] RIP [] dump_page_badflags+0x191/0x250 [ 28.282369] RSP [ 28.285967] ---[ end trace 9caeacb0a953a91e ]--- [ 28.792951] Shutting down cpus with NMI [ 28.797449] Dumping ftrace buffer: [ 28.800965] (ftrace buffer empty) [ 28.804643] Kernel Offset: disabled [ 28.808235] Rebooting in 86400 seconds..