[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.655495] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.130068] random: sshd: uninitialized urandom read (32 bytes read) [ 22.463731] random: sshd: uninitialized urandom read (32 bytes read) [ 23.181570] random: sshd: uninitialized urandom read (32 bytes read) [ 23.316684] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.35' (ECDSA) to the list of known hosts. [ 28.728976] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 28.814964] IPVS: ftp: loaded support on port[0] = 21 [ 28.841317] ================================================================== [ 28.848742] BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 [ 28.855604] Read of size 8 at addr ffff8801d76f4f50 by task syz-executor961/4453 [ 28.863129] [ 28.864741] CPU: 0 PID: 4453 Comm: syz-executor961 Not tainted 4.18.0-rc3-next-20180706+ #1 [ 28.873232] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.882576] Call Trace: [ 28.885171] dump_stack+0x1c9/0x2b4 [ 28.888794] ? dump_stack_print_info.cold.2+0x52/0x52 [ 28.893968] ? printk+0xa7/0xcf [ 28.897388] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 28.902130] ? find_first_bit+0xf7/0x100 [ 28.906203] print_address_description+0x6c/0x20b [ 28.911040] ? find_first_bit+0xf7/0x100 [ 28.915082] kasan_report.cold.7+0x242/0x30d [ 28.919484] __asan_report_load8_noabort+0x14/0x20 [ 28.924408] find_first_bit+0xf7/0x100 [ 28.928278] shrink_slab+0x5d0/0xdb0 [ 28.931980] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 28.937506] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 28.943140] ? shrink_active_list+0x1830/0x1830 [ 28.947802] ? page_add_new_anon_rmap+0x870/0x870 [ 28.952643] ? save_stack+0xa9/0xd0 [ 28.956249] ? save_stack+0x43/0xd0 [ 28.959862] ? kernfs_fop_open+0xa7f/0x1020 [ 28.964173] ? do_dentry_open+0xa7d/0x11c0 [ 28.968389] ? trace_hardirqs_on+0x10/0x10 [ 28.972619] shrink_node+0x429/0x16a0 [ 28.976413] ? shrink_node_memcg+0x18f0/0x18f0 [ 28.980977] ? kvm_clock_read+0x25/0x30 [ 28.984933] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 28.989931] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 28.994406] ? xa_set_tag+0x40/0x40 [ 28.998025] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 29.003034] do_try_to_free_pages+0x3e7/0x1290 [ 29.007618] ? shrink_node+0x16a0/0x16a0 [ 29.011667] ? check_same_owner+0x340/0x340 [ 29.015971] ? trace_hardirqs_on+0x10/0x10 [ 29.020199] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.025721] ? _parse_integer+0x13b/0x190 [ 29.029871] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 29.035047] ? pointer_string+0x1b0/0x1b0 [ 29.039178] ? try_to_free_pages+0xb80/0xb80 [ 29.043571] ? memparse+0x171/0x1d0 [ 29.047187] ? get_options+0x380/0x380 [ 29.051057] ? kasan_kmalloc+0xc4/0xe0 [ 29.054927] ? __kmalloc+0x14e/0x760 [ 29.058711] ? kernfs_fop_write+0x33d/0x480 [ 29.063025] ? __vfs_write+0x117/0x9f0 [ 29.066912] ? vfs_write+0x1fc/0x560 [ 29.070613] ? ksys_write+0x101/0x260 [ 29.074414] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 29.079946] ? page_counter_memparse+0xb5/0x1e0 [ 29.084610] ? page_counter_set_low+0x180/0x180 [ 29.089265] ? cgroup_control+0x180/0x180 [ 29.093395] memory_high_write+0x283/0x310 [ 29.097632] ? mem_cgroup_css_released+0x140/0x140 [ 29.102554] ? lock_acquire+0x1e4/0x540 [ 29.106507] ? __might_fault+0x12b/0x1e0 [ 29.110569] cgroup_file_write+0x31f/0x840 [ 29.114790] ? mem_cgroup_css_released+0x140/0x140 [ 29.119714] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 29.124801] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 29.129713] kernfs_fop_write+0x2ba/0x480 [ 29.133844] __vfs_write+0x117/0x9f0 [ 29.137539] ? kernfs_fop_open+0x1020/0x1020 [ 29.141937] ? kernel_read+0x120/0x120 [ 29.145808] ? lock_release+0xa30/0xa30 [ 29.149764] ? check_same_owner+0x340/0x340 [ 29.154078] ? rcu_note_context_switch+0x730/0x730 [ 29.158993] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.164521] ? __sb_start_write+0x17f/0x300 [ 29.168834] vfs_write+0x1fc/0x560 [ 29.172357] ksys_write+0x101/0x260 [ 29.175976] ? __ia32_sys_read+0xb0/0xb0 [ 29.180021] __x64_sys_write+0x73/0xb0 [ 29.183899] do_syscall_64+0x1b9/0x820 [ 29.187781] ? syscall_return_slowpath+0x5e0/0x5e0 [ 29.192702] ? syscall_return_slowpath+0x31d/0x5e0 [ 29.197735] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 29.202742] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.208273] ? prepare_exit_to_usermode+0x291/0x3b0 [ 29.213270] ? perf_trace_sys_enter+0xb10/0xb10 [ 29.217941] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.222767] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.227938] RIP: 0033:0x441a29 [ 29.231119] 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 [ 29.250272] RSP: 002b:00007ffc285a1848 EFLAGS: 00000206 ORIG_RAX: 0000000000000001 [ 29.257961] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441a29 [ 29.265213] RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 [ 29.272472] RBP: 0000000000000000 R08: 0000000000000012 R09: 0000000000000006 [ 29.279736] R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 [ 29.286998] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 29.294259] [ 29.295866] Allocated by task 4452: [ 29.299481] save_stack+0x43/0xd0 [ 29.302927] kasan_kmalloc+0xc4/0xe0 [ 29.306623] __kmalloc_node+0x47/0x70 [ 29.310416] kvmalloc_node+0x65/0xf0 [ 29.314109] mem_cgroup_css_online+0x169/0x3c0 [ 29.318689] online_css+0x10c/0x350 [ 29.322298] cgroup_apply_control_enable+0x777/0xe90 [ 29.327382] cgroup_mkdir+0x88a/0x1170 [ 29.331252] kernfs_iop_mkdir+0x159/0x1e0 [ 29.335389] vfs_mkdir+0x42e/0x6b0 [ 29.338908] do_mkdirat+0x27b/0x310 [ 29.342533] __x64_sys_mkdir+0x5c/0x80 [ 29.346416] do_syscall_64+0x1b9/0x820 [ 29.350311] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.355492] [ 29.357113] Freed by task 2873: [ 29.360378] save_stack+0x43/0xd0 [ 29.363822] __kasan_slab_free+0x11a/0x170 [ 29.368038] kasan_slab_free+0xe/0x10 [ 29.371822] kfree+0xd9/0x260 [ 29.374918] single_release+0x8f/0xb0 [ 29.378702] __fput+0x35d/0x930 [ 29.382011] ____fput+0x15/0x20 [ 29.385283] task_work_run+0x1ec/0x2a0 [ 29.389150] exit_to_usermode_loop+0x313/0x370 [ 29.393718] do_syscall_64+0x6be/0x820 [ 29.397605] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.402973] [ 29.404599] The buggy address belongs to the object at ffff8801d76f4f40 [ 29.404599] which belongs to the cache kmalloc-32 of size 32 [ 29.417065] The buggy address is located 16 bytes inside of [ 29.417065] 32-byte region [ffff8801d76f4f40, ffff8801d76f4f60) [ 29.428777] The buggy address belongs to the page: [ 29.433696] page:ffffea00075dbd00 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d76f4fc1 [ 29.443132] flags: 0x2fffc0000000100(slab) [ 29.447359] raw: 02fffc0000000100 ffffea0006c88f88 ffffea00075dc548 ffff8801da8001c0 [ 29.455224] raw: ffff8801d76f4fc1 ffff8801d76f4000 000000010000001a 0000000000000000 [ 29.463080] page dumped because: kasan: bad access detected [ 29.468767] [ 29.470371] Memory state around the buggy address: [ 29.475290] ffff8801d76f4e00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 29.482644] ffff8801d76f4e80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc [ 29.489996] >ffff8801d76f4f00: 00 07 fc fc fc fc fc fc 00 00 05 fc fc fc fc fc [ 29.497344] ^ [ 29.503294] ffff8801d76f4f80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc [ 29.510642] ffff8801d76f5000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 29.517986] ================================================================== [ 29.525428] Kernel panic - not syncing: panic_on_warn set ... [ 29.525428] [ 29.532787] CPU: 0 PID: 4453 Comm: syz-executor961 Tainted: G B 4.18.0-rc3-next-20180706+ #1 [ 29.542663] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.552016] Call Trace: [ 29.554604] dump_stack+0x1c9/0x2b4 [ 29.558229] ? dump_stack_print_info.cold.2+0x52/0x52 [ 29.563413] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.568163] panic+0x238/0x4e7 [ 29.571346] ? add_taint.cold.5+0x16/0x16 [ 29.575478] ? do_raw_spin_unlock+0xa7/0x2f0 [ 29.579872] ? find_first_bit+0xf7/0x100 [ 29.583925] kasan_end_report+0x47/0x4f [ 29.588006] kasan_report.cold.7+0x76/0x30d [ 29.592320] __asan_report_load8_noabort+0x14/0x20 [ 29.597231] find_first_bit+0xf7/0x100 [ 29.601101] shrink_slab+0x5d0/0xdb0 [ 29.604799] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 29.610334] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 29.615954] ? shrink_active_list+0x1830/0x1830 [ 29.620620] ? page_add_new_anon_rmap+0x870/0x870 [ 29.625444] ? save_stack+0xa9/0xd0 [ 29.629498] ? save_stack+0x43/0xd0 [ 29.633114] ? kernfs_fop_open+0xa7f/0x1020 [ 29.637428] ? do_dentry_open+0xa7d/0x11c0 [ 29.641647] ? trace_hardirqs_on+0x10/0x10 [ 29.645867] shrink_node+0x429/0x16a0 [ 29.649656] ? shrink_node_memcg+0x18f0/0x18f0 [ 29.654221] ? kvm_clock_read+0x25/0x30 [ 29.658176] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 29.663189] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 29.667727] ? xa_set_tag+0x40/0x40 [ 29.671357] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 29.676357] do_try_to_free_pages+0x3e7/0x1290 [ 29.681274] ? shrink_node+0x16a0/0x16a0 [ 29.685329] ? check_same_owner+0x340/0x340 [ 29.689646] ? trace_hardirqs_on+0x10/0x10 [ 29.693877] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.699399] ? _parse_integer+0x13b/0x190 [ 29.703555] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 29.709185] ? pointer_string+0x1b0/0x1b0 [ 29.713322] ? try_to_free_pages+0xb80/0xb80 [ 29.717716] ? memparse+0x171/0x1d0 [ 29.721338] ? get_options+0x380/0x380 [ 29.725211] ? kasan_kmalloc+0xc4/0xe0 [ 29.729082] ? __kmalloc+0x14e/0x760 [ 29.732791] ? kernfs_fop_write+0x33d/0x480 [ 29.737097] ? __vfs_write+0x117/0x9f0 [ 29.740973] ? vfs_write+0x1fc/0x560 [ 29.744666] ? ksys_write+0x101/0x260 [ 29.748451] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 29.753986] ? page_counter_memparse+0xb5/0x1e0 [ 29.758647] ? page_counter_set_low+0x180/0x180 [ 29.763298] ? cgroup_control+0x180/0x180 [ 29.767434] memory_high_write+0x283/0x310 [ 29.771663] ? mem_cgroup_css_released+0x140/0x140 [ 29.776582] ? lock_acquire+0x1e4/0x540 [ 29.780552] ? __might_fault+0x12b/0x1e0 [ 29.784605] cgroup_file_write+0x31f/0x840 [ 29.788842] ? mem_cgroup_css_released+0x140/0x140 [ 29.793764] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 29.798680] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 29.803593] kernfs_fop_write+0x2ba/0x480 [ 29.807723] __vfs_write+0x117/0x9f0 [ 29.811416] ? kernfs_fop_open+0x1020/0x1020 [ 29.815812] ? kernel_read+0x120/0x120 [ 29.819697] ? lock_release+0xa30/0xa30 [ 29.823659] ? check_same_owner+0x340/0x340 [ 29.827968] ? rcu_note_context_switch+0x730/0x730 [ 29.832888] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.838410] ? __sb_start_write+0x17f/0x300 [ 29.842716] vfs_write+0x1fc/0x560 [ 29.846251] ksys_write+0x101/0x260 [ 29.849867] ? __ia32_sys_read+0xb0/0xb0 [ 29.853908] __x64_sys_write+0x73/0xb0 [ 29.857779] do_syscall_64+0x1b9/0x820 [ 29.861658] ? syscall_return_slowpath+0x5e0/0x5e0 [ 29.866585] ? syscall_return_slowpath+0x31d/0x5e0 [ 29.871518] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 29.876519] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 29.882040] ? prepare_exit_to_usermode+0x291/0x3b0 [ 29.887047] ? perf_trace_sys_enter+0xb10/0xb10 [ 29.891701] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.896527] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 29.901712] RIP: 0033:0x441a29 [ 29.904890] 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 [ 29.924017] RSP: 002b:00007ffc285a1848 EFLAGS: 00000206 ORIG_RAX: 0000000000000001 [ 29.931726] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441a29 [ 29.938984] RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 [ 29.946237] RBP: 0000000000000000 R08: 0000000000000012 R09: 0000000000000006 [ 29.953489] R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 [ 29.960741] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 29.968426] Dumping ftrace buffer: [ 29.972057] (ftrace buffer empty) [ 29.975750] Kernel Offset: disabled [ 29.979371] Rebooting in 86400 seconds..