[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.319951] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.621583] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 21.947370] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available) [ 22.781840] random: sshd: uninitialized urandom read (32 bytes read, 96 bits of entropy available) [ 38.336056] random: sshd: uninitialized urandom read (32 bytes read, 108 bits of entropy available) Warning: Permanently added '10.128.0.44' (ECDSA) to the list of known hosts. [ 43.721230] random: sshd: uninitialized urandom read (32 bytes read, 114 bits of entropy available) executing program [ 43.824557] ================================================================== [ 43.831946] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 43.838582] Read of size 8 at addr ffff8801d31999b8 by task syzkaller524473/3338 [ 43.846082] [ 43.847683] CPU: 0 PID: 3338 Comm: syzkaller524473 Not tainted 4.4.111-g1849cd3 #19 [ 43.855451] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.864777] 0000000000000000 2ea9d1c8308630b6 ffff8801cfc6f850 ffffffff81d0509d [ 43.872750] ffffea00074c6600 ffff8801d31999b8 0000000000000000 ffff8801d31999b8 [ 43.880724] 0000000000000000 ffff8801cfc6f888 ffffffff814fd433 ffff8801d31999b8 [ 43.888689] Call Trace: [ 43.891248] [] dump_stack+0xc1/0x124 [ 43.896583] [] print_address_description+0x73/0x260 [ 43.903218] [] kasan_report+0x285/0x370 [ 43.908810] [] ? __lock_acquire+0x387e/0x4b50 [ 43.914930] [] __asan_report_load8_noabort+0x14/0x20 [ 43.921652] [] __lock_acquire+0x387e/0x4b50 [ 43.927591] [] ? __lock_acquire+0xb5f/0x4b50 [ 43.933618] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 43.940611] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 43.947420] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 43.954403] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 43.961384] [] lock_acquire+0x15e/0x460 [ 43.966979] [] ? remove_wait_queue+0x14/0x40 [ 43.973009] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 43.979383] [] ? remove_wait_queue+0x14/0x40 [ 43.985411] [] remove_wait_queue+0x14/0x40 [ 43.991290] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 43.998278] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 44.005531] [] ? ep_free+0x1c0/0x1c0 [ 44.010866] [] ep_free+0x93/0x1c0 [ 44.015938] [] ? ep_free+0x1c0/0x1c0 [ 44.021273] [] ep_eventpoll_release+0x44/0x60 [ 44.027387] [] __fput+0x233/0x6d0 [ 44.032459] [] ____fput+0x15/0x20 [ 44.037532] [] task_work_run+0x104/0x180 [ 44.043210] [] do_exit+0x871/0x2a20 [ 44.048463] [] ? handle_mm_fault+0x192d/0x3190 [ 44.054665] [] ? handle_mm_fault+0x3f2/0x3190 [ 44.060783] [] ? release_task+0x1240/0x1240 [ 44.066724] [] do_group_exit+0x108/0x320 [ 44.072410] [] SyS_exit_group+0x1d/0x20 [ 44.078006] [] ? do_group_exit+0x320/0x320 [ 44.083859] [] do_fast_syscall_32+0x314/0x890 [ 44.089987] [] sysenter_flags_fixed+0xd/0x17 [ 44.096030] [ 44.097624] Allocated by task 3338: [ 44.101226] [] save_stack_trace+0x26/0x50 [ 44.107113] [] save_stack+0x43/0xd0 [ 44.112473] [] kasan_kmalloc+0xad/0xe0 [ 44.118110] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 44.124686] [] binder_get_thread+0x181/0x7a0 [ 44.130829] [] binder_poll+0x4a/0x210 [ 44.136363] [] SyS_epoll_ctl+0x10b1/0x2050 [ 44.142335] [] do_fast_syscall_32+0x314/0x890 [ 44.148575] [] sysenter_flags_fixed+0xd/0x17 [ 44.154716] [ 44.156312] Freed by task 3338: [ 44.159568] [] save_stack_trace+0x26/0x50 [ 44.165458] [] save_stack+0x43/0xd0 [ 44.170820] [] kasan_slab_free+0x72/0xc0 [ 44.176614] [] kfree+0xfc/0x300 [ 44.181636] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 44.188386] [] binder_thread_release+0x27d/0x540 [ 44.194884] [] binder_ioctl+0xb94/0x12e0 [ 44.200683] [] compat_SyS_ioctl+0x28a/0x2540 [ 44.206829] [] do_fast_syscall_32+0x314/0x890 [ 44.213062] [] sysenter_flags_fixed+0xd/0x17 [ 44.219204] [ 44.220812] The buggy address belongs to the object at ffff8801d3199900 [ 44.220812] which belongs to the cache kmalloc-512 of size 512 [ 44.233449] The buggy address is located 184 bytes inside of [ 44.233449] 512-byte region [ffff8801d3199900, ffff8801d3199b00) [ 44.245294] The buggy address belongs to the page: [ 45.697236] PANIC: double fault, error_code: 0x0 [ 45.702006] CPU: 0 PID: 3338 Comm: syzkaller524473 Not tainted 4.4.111-g1849cd3 #19 [ 45.709787] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.719113] task: ffff8800b49497c0 task.stack: ffff8801cfc68000 [ 45.725139] RIP: 0010:[] [] dump_page_badflags+0x1a/0x250 [ 45.733998] RSP: 0018:ffff880100000000 EFLAGS: 00010086 [ 45.739416] RAX: ffff8800b49497c0 RBX: ffffea00074c6600 RCX: ffffffff8148f980 [ 45.746657] RDX: 0000000000000000 RSI: ffffffff838a8360 RDI: ffffea00074c6600 [ 45.753897] RBP: ffff880100000030 R08: 0000000000000001 R09: 0000000000000000 [ 45.761147] R10: 0000000000000002 R11: fffffbfff0ad781e R12: 0000000000000000 [ 45.768387] R13: ffffffff838a8360 R14: 0000000000000000 R15: 0000000000000000 [ 45.775626] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 45.783820] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 45.789680] CR2: ffff8800fffffff8 CR3: 000000000420c000 CR4: 0000000000160670 [ 45.796930] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 45.804180] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 45.811420] Stack: [ 45.813538] [ 45.815132] Call Trace: [ 45.817693] [ 45.819722] 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 [ 45.846572] Kernel panic - not syncing: Machine halted. [ 45.851906] CPU: 0 PID: 3338 Comm: syzkaller524473 Not tainted 4.4.111-g1849cd3 #19 [ 45.859674] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.869001] 0000000000000000 2ea9d1c8308630b6 ffff8801db20ce38 ffffffff81d0509d [ 45.876968] ffffffff838367c0 ffff8801db20cf10 ffffffff83808040 ffff880100000000 [ 45.884934] 0000000000000000 ffff8801db20cf00 ffffffff81419a3a 0000000041b58ab3 [ 45.892906] Call Trace: [ 45.895455] <#DF> [] dump_stack+0xc1/0x124 [ 45.901523] [] panic+0x1aa/0x388 [ 45.906514] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 45.913415] [] ? vprintk_emit+0x242/0x850 [ 45.919190] [] ? dump_page_badflags+0x2f/0x250 [ 45.925388] [] ? vprintk_emit+0x242/0x850 [ 45.931157] [] df_debug+0x2d/0x30 [ 45.936231] [] do_double_fault+0x10b/0x210 [ 45.942092] [] double_fault+0x2d/0x40 [ 45.947512] [] ? dump_page_badflags+0x180/0x250 [ 45.953798] [] ? dump_page_badflags+0x1a/0x250 [ 45.959995] <> [ 45.963288] Dumping ftrace buffer: [ 45.967088] (ftrace buffer empty) [ 45.970769] Kernel Offset: disabled [ 45.974364] Rebooting in 86400 seconds..