[ 15.870550] 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: [ 20.997299] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 21.340968] random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) [ 22.017158] random: sshd: uninitialized urandom read (32 bytes read, 71 bits of entropy available) [ 22.188570] random: sshd: uninitialized urandom read (32 bytes read, 76 bits of entropy available) Warning: Permanently added '10.128.0.16' (ECDSA) to the list of known hosts. [ 27.604932] random: sshd: uninitialized urandom read (32 bytes read, 84 bits of entropy available) executing program [ 27.692994] ================================================================== [ 27.700374] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.707006] Read of size 8 at addr ffff8800b4a9b238 by task syzkaller124859/3310 [ 27.714510] [ 27.716110] CPU: 1 PID: 3310 Comm: syzkaller124859 Not tainted 4.4.111-g3301b55 #24 [ 27.723867] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.733189] 0000000000000000 411bbc906310182a ffff8801d049f8d0 ffffffff81d0509d [ 27.741141] ffffea0002d2a680 ffff8800b4a9b238 0000000000000000 ffff8800b4a9b238 [ 27.749119] 0000000000000000 ffff8801d049f908 ffffffff814fd433 ffff8800b4a9b238 [ 27.757079] Call Trace: [ 27.759637] [] dump_stack+0xc1/0x124 [ 27.764970] [] print_address_description+0x73/0x260 [ 27.771614] [] kasan_report+0x285/0x370 [ 27.777205] [] ? __lock_acquire+0x387e/0x4b50 [ 27.783330] [] __asan_report_load8_noabort+0x14/0x20 [ 27.790049] [] __lock_acquire+0x387e/0x4b50 [ 27.795984] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.802017] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.809002] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.815981] [] ? mark_held_locks+0xaf/0x100 [ 27.821916] [] lock_acquire+0x15e/0x460 [ 27.827520] [] ? remove_wait_queue+0x14/0x40 [ 27.833547] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.839841] [] ? remove_wait_queue+0x14/0x40 [ 27.846048] [] remove_wait_queue+0x14/0x40 [ 27.851902] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.858887] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.866127] [] ? ep_free+0x1c0/0x1c0 [ 27.871455] [] ep_free+0x93/0x1c0 [ 27.876522] [] ? ep_free+0x1c0/0x1c0 [ 27.881864] [] ep_eventpoll_release+0x44/0x60 [ 27.887978] [] __fput+0x233/0x6d0 [ 27.893065] [] ____fput+0x15/0x20 [ 27.898150] [] task_work_run+0x104/0x180 [ 27.903845] [] do_exit+0x871/0x2a20 [ 27.909093] [] ? release_task+0x1240/0x1240 [ 27.915044] [] ? SyS_epoll_create+0x190/0x190 [ 27.921157] [] do_group_exit+0x108/0x320 [ 27.926834] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.933297] [] SyS_exit_group+0x1d/0x20 [ 27.938999] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.945539] [ 27.947135] Allocated by task 3310: [ 27.950731] [] save_stack_trace+0x26/0x50 [ 27.956633] [] save_stack+0x43/0xd0 [ 27.961992] [] kasan_kmalloc+0xad/0xe0 [ 27.967615] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.974196] [] binder_get_thread+0x181/0x7a0 [ 27.980332] [] binder_poll+0x4a/0x210 [ 27.985859] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.991823] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.998835] [ 28.000427] Freed by task 3310: [ 28.003668] [] save_stack_trace+0x26/0x50 [ 28.009557] [] save_stack+0x43/0xd0 [ 28.014918] [] kasan_slab_free+0x72/0xc0 [ 28.020720] [] kfree+0xfc/0x300 [ 28.025736] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 28.032481] [] binder_thread_release+0x27d/0x540 [ 28.038968] [] binder_ioctl+0xb94/0x12e0 [ 28.044773] [] do_vfs_ioctl+0x7aa/0xee0 [ 28.050479] [] SyS_ioctl+0x8f/0xc0 [ 28.055767] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 28.062427] [ 28.064031] The buggy address belongs to the object at ffff8800b4a9b180 [ 28.064031] which belongs to the cache kmalloc-512 of size 512 [ 28.076650] The buggy address is located 184 bytes inside of [ 28.076650] 512-byte region [ffff8800b4a9b180, ffff8800b4a9b380) [ 28.088504] The buggy address belongs to the page: [ 29.554027] PANIC: double fault, error_code: 0x0 [ 29.558973] CPU: 1 PID: 3310 Comm: syzkaller124859 Not tainted 4.4.111-g3301b55 #24 [ 29.566738] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.576060] task: ffff8801d1ef0000 task.stack: ffff8801d0498000 [ 29.582080] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 29.590916] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 29.596330] RAX: ffff8801d1ef0000 RBX: ffffea0002d2a680 RCX: ffffffff8148f980 [ 29.603581] RDX: 0000000000000000 RSI: ffffffff838a83a0 RDI: ffffea0002d2a680 [ 29.610816] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 29.618668] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 29.625904] R13: ffffffff838a83a0 R14: 0000000000000000 R15: 0000000000000000 [ 29.633141] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.641337] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.647183] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 29.654428] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.661750] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.668983] Stack: [ 29.671108] [ 29.672709] Call Trace: [ 29.675258] [ 29.677284] 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 [ 29.703967] Kernel panic - not syncing: Machine halted. [ 29.709304] CPU: 1 PID: 3310 Comm: syzkaller124859 Not tainted 4.4.111-g3301b55 #24 [ 29.717060] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.726386] 0000000000000000 411bbc906310182a ffff8801db30ce38 ffffffff81d0509d [ 29.734332] ffffffff838367c0 ffff8801db30cf10 ffffffff83808040 ffff880100000000 [ 29.742282] 0000000000000000 ffff8801db30cf00 ffffffff81419a3a 0000000041b58ab3 [ 29.750235] Call Trace: [ 29.752782] <#DF> [] dump_stack+0xc1/0x124 [ 29.758840] [] panic+0x1aa/0x388 [ 29.763822] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 29.770720] [] ? vprintk_emit+0x242/0x850 [ 29.776483] [] ? dump_page_badflags+0x2f/0x250 [ 29.782679] [] ? vprintk_emit+0x242/0x850 [ 29.788441] [] df_debug+0x2d/0x30 [ 29.793511] [] do_double_fault+0x10b/0x210 [ 29.799363] [] double_fault+0x2d/0x40 [ 29.804778] [] ? dump_page_badflags+0x180/0x250 [ 29.811147] [] ? dump_page_badflags+0x1a/0x250 [ 29.817340] <> [ 29.820730] Dumping ftrace buffer: [ 29.824539] (ftrace buffer empty) [ 29.828216] Kernel Offset: disabled [ 29.831807] Rebooting in 86400 seconds..