[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.679407] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 16.765141] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.960472] random: sshd: uninitialized urandom read (32 bytes read) [ 17.610048] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.19' (ECDSA) to the list of known hosts. [ 23.216220] urandom_read: 1 callbacks suppressed [ 23.216225] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 23.306351] IPVS: ftp: loaded support on port[0] = 21 [ 23.332547] ================================================================== [ 23.339957] BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 [ 23.346699] Read of size 8 at addr ffff8801d7845b10 by task syz-executor437/4452 [ 23.354204] [ 23.355818] CPU: 1 PID: 4452 Comm: syz-executor437 Not tainted 4.18.0-rc3-next-20180706+ #1 [ 23.364456] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.373790] Call Trace: [ 23.376364] dump_stack+0x1c9/0x2b4 [ 23.379979] ? dump_stack_print_info.cold.2+0x52/0x52 [ 23.385153] ? printk+0xa7/0xcf [ 23.388412] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 23.393149] ? find_first_bit+0xf7/0x100 [ 23.397213] print_address_description+0x6c/0x20b [ 23.402047] ? find_first_bit+0xf7/0x100 [ 23.406094] kasan_report.cold.7+0x242/0x30d [ 23.410492] __asan_report_load8_noabort+0x14/0x20 [ 23.415408] find_first_bit+0xf7/0x100 [ 23.419276] shrink_slab+0x5d0/0xdb0 [ 23.422971] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 23.428498] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 23.434104] ? shrink_active_list+0x1830/0x1830 [ 23.438755] ? save_stack+0xa9/0xd0 [ 23.442363] ? save_stack+0x43/0xd0 [ 23.445972] ? kernfs_fop_open+0xa7f/0x1020 [ 23.450274] ? do_dentry_open+0xa7d/0x11c0 [ 23.454491] ? trace_hardirqs_on+0x10/0x10 [ 23.458720] shrink_node+0x429/0x16a0 [ 23.462518] ? shrink_node_memcg+0x18f0/0x18f0 [ 23.467097] ? kvm_clock_read+0x25/0x30 [ 23.471053] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 23.476056] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 23.480537] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 23.485536] do_try_to_free_pages+0x3e7/0x1290 [ 23.490100] ? shrink_node+0x16a0/0x16a0 [ 23.494140] ? check_same_owner+0x340/0x340 [ 23.498440] ? trace_hardirqs_on+0x10/0x10 [ 23.502655] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 23.508169] ? _parse_integer+0x13b/0x190 [ 23.512308] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 23.517826] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 23.522995] ? pointer_string+0x1b0/0x1b0 [ 23.527132] ? try_to_free_pages+0xb80/0xb80 [ 23.531524] ? memparse+0x171/0x1d0 [ 23.535131] ? get_options+0x380/0x380 [ 23.539000] ? kasan_kmalloc+0xc4/0xe0 [ 23.542878] ? __kmalloc+0x14e/0x760 [ 23.546572] ? kernfs_fop_write+0x33d/0x480 [ 23.550875] ? __vfs_write+0x117/0x9f0 [ 23.554739] ? vfs_write+0x1fc/0x560 [ 23.558446] ? ksys_write+0x101/0x260 [ 23.562239] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 23.567760] ? page_counter_memparse+0xb5/0x1e0 [ 23.572411] ? page_counter_set_low+0x180/0x180 [ 23.577063] ? cgroup_control+0x180/0x180 [ 23.581196] memory_high_write+0x283/0x310 [ 23.585423] ? mem_cgroup_css_released+0x140/0x140 [ 23.590362] ? lock_acquire+0x1e4/0x540 [ 23.594330] ? __might_fault+0x12b/0x1e0 [ 23.598379] cgroup_file_write+0x31f/0x840 [ 23.602597] ? mem_cgroup_css_released+0x140/0x140 [ 23.607506] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 23.612415] ? __might_fault+0x1a3/0x1e0 [ 23.616458] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 23.621368] kernfs_fop_write+0x2ba/0x480 [ 23.625502] __vfs_write+0x117/0x9f0 [ 23.629210] ? kernfs_fop_open+0x1020/0x1020 [ 23.633600] ? kernel_read+0x120/0x120 [ 23.637470] ? lock_release+0xa30/0xa30 [ 23.641428] ? check_same_owner+0x340/0x340 [ 23.645728] ? rcu_note_context_switch+0x730/0x730 [ 23.650639] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 23.656157] ? __sb_start_write+0x17f/0x300 [ 23.660459] vfs_write+0x1fc/0x560 [ 23.663981] ksys_write+0x101/0x260 [ 23.667589] ? __ia32_sys_read+0xb0/0xb0 [ 23.671632] __x64_sys_write+0x73/0xb0 [ 23.675511] do_syscall_64+0x1b9/0x820 [ 23.679385] ? syscall_return_slowpath+0x5e0/0x5e0 [ 23.684306] ? syscall_return_slowpath+0x31d/0x5e0 [ 23.689215] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 23.694208] ? prepare_exit_to_usermode+0x291/0x3b0 [ 23.699211] ? perf_trace_sys_enter+0xb10/0xb10 [ 23.703874] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 23.708696] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 23.713890] RIP: 0033:0x4419d9 [ 23.717068] Code: e8 ec b5 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 23.736194] RSP: 002b:00007ffc5168b348 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 23.743889] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 23.751140] RDX: 0000000000000000 RSI: 0000000020000740 RDI: 0000000000000004 [ 23.758388] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 23.765635] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 23.772892] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 23.780145] [ 23.781750] Allocated by task 4451: [ 23.785364] save_stack+0x43/0xd0 [ 23.788796] kasan_kmalloc+0xc4/0xe0 [ 23.792490] __kmalloc_node+0x47/0x70 [ 23.796276] kvmalloc_node+0x65/0xf0 [ 23.799968] mem_cgroup_css_online+0x169/0x3c0 [ 23.804529] online_css+0x10c/0x350 [ 23.808138] cgroup_apply_control_enable+0x777/0xe90 [ 23.813229] cgroup_mkdir+0x88a/0x1170 [ 23.817092] kernfs_iop_mkdir+0x159/0x1e0 [ 23.821218] vfs_mkdir+0x42e/0x6b0 [ 23.824736] do_mkdirat+0x27b/0x310 [ 23.828343] __x64_sys_mkdir+0x5c/0x80 [ 23.832212] do_syscall_64+0x1b9/0x820 [ 23.836098] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 23.841296] [ 23.842917] Freed by task 2873: [ 23.846200] save_stack+0x43/0xd0 [ 23.849662] __kasan_slab_free+0x11a/0x170 [ 23.853877] kasan_slab_free+0xe/0x10 [ 23.857656] kfree+0xd9/0x260 [ 23.860741] single_release+0x8f/0xb0 [ 23.864519] __fput+0x35d/0x930 [ 23.867776] ____fput+0x15/0x20 [ 23.871042] task_work_run+0x1ec/0x2a0 [ 23.874912] exit_to_usermode_loop+0x313/0x370 [ 23.879471] do_syscall_64+0x6be/0x820 [ 23.883343] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 23.888506] [ 23.890111] The buggy address belongs to the object at ffff8801d7845b00 [ 23.890111] which belongs to the cache kmalloc-32 of size 32 [ 23.902572] The buggy address is located 16 bytes inside of [ 23.902572] 32-byte region [ffff8801d7845b00, ffff8801d7845b20) [ 23.914246] The buggy address belongs to the page: [ 23.919155] page:ffffea00075e1140 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d7845fc1 [ 23.928588] flags: 0x2fffc0000000100(slab) [ 23.932806] raw: 02fffc0000000100 ffffea00075e2008 ffff8801da801248 ffff8801da8001c0 [ 23.940676] raw: ffff8801d7845fc1 ffff8801d7845000 000000010000003f 0000000000000000 [ 23.948531] page dumped because: kasan: bad access detected [ 23.954222] [ 23.955824] Memory state around the buggy address: [ 23.960736] ffff8801d7845a00: 00 00 00 fc fc fc fc fc 00 fc fc fc fc fc fc fc [ 23.968079] ffff8801d7845a80: 00 07 fc fc fc fc fc fc fb fb fb fb fc fc fc fc [ 23.975423] >ffff8801d7845b00: 00 00 05 fc fc fc fc fc 00 00 00 fc fc fc fc fc [ 23.982756] ^ [ 23.986621] ffff8801d7845b80: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc [ 23.993957] ffff8801d7845c00: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc [ 24.001292] ================================================================== [ 24.008729] Kernel panic - not syncing: panic_on_warn set ... [ 24.008729] [ 24.016094] CPU: 1 PID: 4452 Comm: syz-executor437 Tainted: G B 4.18.0-rc3-next-20180706+ #1 [ 24.025949] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.035281] Call Trace: [ 24.037859] dump_stack+0x1c9/0x2b4 [ 24.041467] ? dump_stack_print_info.cold.2+0x52/0x52 [ 24.046645] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 24.051383] panic+0x238/0x4e7 [ 24.054556] ? add_taint.cold.5+0x16/0x16 [ 24.058686] ? do_raw_spin_unlock+0xa7/0x2f0 [ 24.063073] ? find_first_bit+0xf7/0x100 [ 24.067126] kasan_end_report+0x47/0x4f [ 24.071080] kasan_report.cold.7+0x76/0x30d [ 24.075383] __asan_report_load8_noabort+0x14/0x20 [ 24.080297] find_first_bit+0xf7/0x100 [ 24.084164] shrink_slab+0x5d0/0xdb0 [ 24.087862] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 24.093381] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 24.098984] ? shrink_active_list+0x1830/0x1830 [ 24.103647] ? save_stack+0xa9/0xd0 [ 24.107266] ? save_stack+0x43/0xd0 [ 24.110874] ? kernfs_fop_open+0xa7f/0x1020 [ 24.115197] ? do_dentry_open+0xa7d/0x11c0 [ 24.119422] ? trace_hardirqs_on+0x10/0x10 [ 24.123639] shrink_node+0x429/0x16a0 [ 24.127425] ? shrink_node_memcg+0x18f0/0x18f0 [ 24.131995] ? kvm_clock_read+0x25/0x30 [ 24.135959] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 24.140953] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 24.145430] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 24.150437] do_try_to_free_pages+0x3e7/0x1290 [ 24.155019] ? shrink_node+0x16a0/0x16a0 [ 24.159070] ? check_same_owner+0x340/0x340 [ 24.163373] ? trace_hardirqs_on+0x10/0x10 [ 24.167591] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 24.173107] ? _parse_integer+0x13b/0x190 [ 24.177241] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 24.182759] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 24.187937] ? pointer_string+0x1b0/0x1b0 [ 24.192076] ? try_to_free_pages+0xb80/0xb80 [ 24.196467] ? memparse+0x171/0x1d0 [ 24.200070] ? get_options+0x380/0x380 [ 24.203940] ? kasan_kmalloc+0xc4/0xe0 [ 24.207893] ? __kmalloc+0x14e/0x760 [ 24.211590] ? kernfs_fop_write+0x33d/0x480 [ 24.215891] ? __vfs_write+0x117/0x9f0 [ 24.219755] ? vfs_write+0x1fc/0x560 [ 24.223447] ? ksys_write+0x101/0x260 [ 24.227246] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 24.232771] ? page_counter_memparse+0xb5/0x1e0 [ 24.237428] ? page_counter_set_low+0x180/0x180 [ 24.242090] ? cgroup_control+0x180/0x180 [ 24.246224] memory_high_write+0x283/0x310 [ 24.250449] ? mem_cgroup_css_released+0x140/0x140 [ 24.255359] ? lock_acquire+0x1e4/0x540 [ 24.259320] ? __might_fault+0x12b/0x1e0 [ 24.263390] cgroup_file_write+0x31f/0x840 [ 24.267607] ? mem_cgroup_css_released+0x140/0x140 [ 24.272516] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 24.277428] ? __might_fault+0x1a3/0x1e0 [ 24.281469] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 24.286395] kernfs_fop_write+0x2ba/0x480 [ 24.290539] __vfs_write+0x117/0x9f0 [ 24.294233] ? kernfs_fop_open+0x1020/0x1020 [ 24.298628] ? kernel_read+0x120/0x120 [ 24.302501] ? lock_release+0xa30/0xa30 [ 24.306462] ? check_same_owner+0x340/0x340 [ 24.310765] ? rcu_note_context_switch+0x730/0x730 [ 24.315679] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 24.321194] ? __sb_start_write+0x17f/0x300 [ 24.325496] vfs_write+0x1fc/0x560 [ 24.329022] ksys_write+0x101/0x260 [ 24.332654] ? __ia32_sys_read+0xb0/0xb0 [ 24.336707] __x64_sys_write+0x73/0xb0 [ 24.340574] do_syscall_64+0x1b9/0x820 [ 24.344441] ? syscall_return_slowpath+0x5e0/0x5e0 [ 24.349350] ? syscall_return_slowpath+0x31d/0x5e0 [ 24.354759] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 24.359757] ? prepare_exit_to_usermode+0x291/0x3b0 [ 24.364753] ? perf_trace_sys_enter+0xb10/0xb10 [ 24.369403] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 24.374231] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 24.379399] RIP: 0033:0x4419d9 [ 24.382563] Code: e8 ec b5 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 24.401690] RSP: 002b:00007ffc5168b348 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 24.409392] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419d9 [ 24.416643] RDX: 0000000000000000 RSI: 0000000020000740 RDI: 0000000000000004 [ 24.423893] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 24.431144] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 24.438394] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 24.446206] Dumping ftrace buffer: [ 24.449727] (ftrace buffer empty) [ 24.453421] Kernel Offset: disabled [ 24.457026] Rebooting in 86400 seconds..