[ 16.013578] 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: [ 21.529896] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.729752] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 22.479327] random: sshd: uninitialized urandom read (32 bytes read, 83 bits of entropy available) [ 24.844329] random: sshd: uninitialized urandom read (32 bytes read, 89 bits of entropy available) Warning: Permanently added '10.128.15.210' (ECDSA) to the list of known hosts. [ 30.221833] random: sshd: uninitialized urandom read (32 bytes read, 97 bits of entropy available) executing program [ 30.321988] ================================================================== [ 30.329408] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 30.336053] Read of size 8 at addr ffff8800b44285b8 by task syzkaller033943/3322 [ 30.343553] [ 30.345151] CPU: 0 PID: 3322 Comm: syzkaller033943 Not tainted 4.4.111-g7902639 #25 [ 30.352913] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.362236] 0000000000000000 b6b408972b1a5c53 ffff8801cd3a78d0 ffffffff81d0509d [ 30.370196] ffffea0002d10a00 ffff8800b44285b8 0000000000000000 ffff8800b44285b8 [ 30.378186] 0000000000000000 ffff8801cd3a7908 ffffffff814fd433 ffff8800b44285b8 [ 30.386155] Call Trace: [ 30.388712] [] dump_stack+0xc1/0x124 [ 30.394050] [] print_address_description+0x73/0x260 [ 30.400680] [] kasan_report+0x285/0x370 [ 30.406269] [] ? __lock_acquire+0x387e/0x4b50 [ 30.412378] [] __asan_report_load8_noabort+0x14/0x20 [ 30.419099] [] __lock_acquire+0x387e/0x4b50 [ 30.425037] [] ? __lock_acquire+0xb5f/0x4b50 [ 30.431073] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 30.438052] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 30.445032] [] ? mark_held_locks+0xaf/0x100 [ 30.450971] [] lock_acquire+0x15e/0x460 [ 30.456563] [] ? remove_wait_queue+0x14/0x40 [ 30.462604] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 30.468892] [] ? remove_wait_queue+0x14/0x40 [ 30.474917] [] remove_wait_queue+0x14/0x40 [ 30.480779] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 30.487763] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 30.495018] [] ? ep_free+0x1c0/0x1c0 [ 30.500347] [] ep_free+0x93/0x1c0 [ 30.505417] [] ? ep_free+0x1c0/0x1c0 [ 30.510756] [] ep_eventpoll_release+0x44/0x60 [ 30.516878] [] __fput+0x233/0x6d0 [ 30.521946] [] ____fput+0x15/0x20 [ 30.527031] [] task_work_run+0x104/0x180 [ 30.532724] [] do_exit+0x871/0x2a20 [ 30.537976] [] ? release_task+0x1240/0x1240 [ 30.543919] [] ? SyS_epoll_create+0x190/0x190 [ 30.550040] [] do_group_exit+0x108/0x320 [ 30.555726] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 30.562185] [] SyS_exit_group+0x1d/0x20 [ 30.567790] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 30.574335] [ 30.575931] Allocated by task 3322: [ 30.579519] [] save_stack_trace+0x26/0x50 [ 30.585420] [] save_stack+0x43/0xd0 [ 30.590778] [] kasan_kmalloc+0xad/0xe0 [ 30.596406] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 30.602990] [] binder_get_thread+0x181/0x7a0 [ 30.609135] [] binder_poll+0x4a/0x210 [ 30.614674] [] SyS_epoll_ctl+0x10b1/0x2050 [ 30.620637] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 30.627297] [ 30.628902] Freed by task 3322: [ 30.632146] [] save_stack_trace+0x26/0x50 [ 30.638036] [] save_stack+0x43/0xd0 [ 30.643404] [] kasan_slab_free+0x72/0xc0 [ 30.649198] [] kfree+0xfc/0x300 [ 30.654220] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 30.660971] [] binder_thread_release+0x27d/0x540 [ 30.667459] [] binder_ioctl+0xb94/0x12e0 [ 30.673252] [] do_vfs_ioctl+0x7aa/0xee0 [ 30.678956] [] SyS_ioctl+0x8f/0xc0 [ 30.684227] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 30.690898] [ 30.692497] The buggy address belongs to the object at ffff8800b4428500 [ 30.692497] which belongs to the cache kmalloc-512 of size 512 [ 30.705133] The buggy address is located 184 bytes inside of [ 30.705133] 512-byte region [ffff8800b4428500, ffff8800b4428700) [ 30.716974] The buggy address belongs to the page: [ 32.201805] PANIC: double fault, error_code: 0x0 [ 32.206595] CPU: 0 PID: 3322 Comm: syzkaller033943 Not tainted 4.4.111-g7902639 #25 [ 32.214357] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.223722] task: ffff8800b57217c0 task.stack: ffff8801cd3a0000 [ 32.229743] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 32.238629] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 32.244049] RAX: ffff8800b57217c0 RBX: ffffea0002d10a00 RCX: ffffffff8148f980 [ 32.251287] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea0002d10a00 [ 32.258533] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 32.265784] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 32.273025] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 32.280270] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 32.289110] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 32.294964] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 32.302462] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 32.309709] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 32.316951] Stack: [ 32.319064] [ 32.320657] Call Trace: [ 32.323205] [ 32.325232] 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 [ 32.352006] Kernel panic - not syncing: Machine halted. [ 32.357346] CPU: 0 PID: 3322 Comm: syzkaller033943 Not tainted 4.4.111-g7902639 #25 [ 32.365126] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.374459] 0000000000000000 b6b408972b1a5c53 ffff8801db20ce38 ffffffff81d0509d [ 32.382425] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 32.390388] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 32.398350] Call Trace: [ 32.400902] <#DF> [] dump_stack+0xc1/0x124 [ 32.406995] [] panic+0x1aa/0x388 [ 32.411998] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 32.418910] [] ? vprintk_emit+0x242/0x850 [ 32.424688] [] ? dump_page_badflags+0x2f/0x250 [ 32.430907] [] ? vprintk_emit+0x242/0x850 [ 32.436680] [] df_debug+0x2d/0x30 [ 32.441757] [] do_double_fault+0x10b/0x210 [ 32.447614] [] double_fault+0x2d/0x40 [ 32.453038] [] ? dump_page_badflags+0x180/0x250 [ 32.459337] [] ? dump_page_badflags+0x1a/0x250 [ 32.465533] <> [ 32.468931] Dumping ftrace buffer: [ 32.472731] (ftrace buffer empty) [ 32.476420] Kernel Offset: disabled [ 32.480023] Rebooting in 86400 seconds..