[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.970426] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.254697] random: sshd: uninitialized urandom read (32 bytes read) [ 18.503895] random: sshd: uninitialized urandom read (32 bytes read) [ 19.184379] random: sshd: uninitialized urandom read (32 bytes read) [ 19.329431] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.47' (ECDSA) to the list of known hosts. [ 24.830253] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 24.922709] IPVS: ftp: loaded support on port[0] = 21 [ 24.952169] ================================================================== [ 24.959602] BUG: KASAN: slab-out-of-bounds in find_first_bit+0xf7/0x100 [ 24.966439] Read of size 8 at addr ffff8801d7877f50 by task syz-executor337/4473 [ 24.973953] [ 24.975572] CPU: 0 PID: 4473 Comm: syz-executor337 Not tainted 4.18.0-rc3-next-20180706+ #1 [ 24.984044] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.993384] Call Trace: [ 24.995977] dump_stack+0x1c9/0x2b4 [ 24.999637] ? dump_stack_print_info.cold.2+0x52/0x52 [ 25.004844] ? printk+0xa7/0xcf [ 25.008137] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 25.012894] ? find_first_bit+0xf7/0x100 [ 25.016951] print_address_description+0x6c/0x20b [ 25.021782] ? find_first_bit+0xf7/0x100 [ 25.025828] kasan_report.cold.7+0x242/0x30d [ 25.030222] __asan_report_load8_noabort+0x14/0x20 [ 25.035135] find_first_bit+0xf7/0x100 [ 25.039012] shrink_slab+0x5d0/0xdb0 [ 25.042728] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.048271] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 25.053901] ? shrink_active_list+0x1830/0x1830 [ 25.058558] ? save_stack+0xa9/0xd0 [ 25.062173] ? save_stack+0x43/0xd0 [ 25.065794] ? kernfs_fop_open+0xa7f/0x1020 [ 25.070110] ? do_dentry_open+0xa7d/0x11c0 [ 25.074348] ? trace_hardirqs_on+0x10/0x10 [ 25.078585] shrink_node+0x429/0x16a0 [ 25.082378] ? shrink_node_memcg+0x18f0/0x18f0 [ 25.086945] ? kvm_clock_read+0x25/0x30 [ 25.090906] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 25.095921] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 25.100405] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 25.105426] do_try_to_free_pages+0x3e7/0x1290 [ 25.110004] ? shrink_node+0x16a0/0x16a0 [ 25.114067] ? check_same_owner+0x340/0x340 [ 25.118385] ? trace_hardirqs_on+0x10/0x10 [ 25.122617] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 25.128163] ? _parse_integer+0x13b/0x190 [ 25.132299] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.137827] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 25.143010] ? pointer_string+0x1b0/0x1b0 [ 25.147144] ? try_to_free_pages+0xb80/0xb80 [ 25.151543] ? memparse+0x171/0x1d0 [ 25.155157] ? get_options+0x380/0x380 [ 25.159033] ? kasan_kmalloc+0xc4/0xe0 [ 25.162915] ? __kmalloc+0x14e/0x760 [ 25.166638] ? kernfs_fop_write+0x33d/0x480 [ 25.170960] ? __vfs_write+0x117/0x9f0 [ 25.174830] ? vfs_write+0x1fc/0x560 [ 25.178527] ? ksys_write+0x101/0x260 [ 25.182317] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.187847] ? page_counter_memparse+0xb5/0x1e0 [ 25.192502] ? page_counter_set_low+0x180/0x180 [ 25.197159] ? cgroup_control+0x180/0x180 [ 25.201302] memory_high_write+0x283/0x310 [ 25.205529] ? mem_cgroup_css_released+0x140/0x140 [ 25.210463] ? lock_acquire+0x1e4/0x540 [ 25.214430] ? __might_fault+0x12b/0x1e0 [ 25.218487] cgroup_file_write+0x31f/0x840 [ 25.222732] ? mem_cgroup_css_released+0x140/0x140 [ 25.227677] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 25.232632] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 25.237567] kernfs_fop_write+0x2ba/0x480 [ 25.241712] __vfs_write+0x117/0x9f0 [ 25.245415] ? kernfs_fop_open+0x1020/0x1020 [ 25.249809] ? kernel_read+0x120/0x120 [ 25.253698] ? lock_release+0xa30/0xa30 [ 25.257659] ? check_same_owner+0x340/0x340 [ 25.261980] ? rcu_note_context_switch+0x730/0x730 [ 25.266911] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 25.272449] ? __sb_start_write+0x17f/0x300 [ 25.276788] vfs_write+0x1fc/0x560 [ 25.280326] ksys_write+0x101/0x260 [ 25.283953] ? __ia32_sys_read+0xb0/0xb0 [ 25.288002] __x64_sys_write+0x73/0xb0 [ 25.291891] do_syscall_64+0x1b9/0x820 [ 25.295771] ? syscall_return_slowpath+0x5e0/0x5e0 [ 25.300712] ? syscall_return_slowpath+0x31d/0x5e0 [ 25.305637] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 25.310643] ? prepare_exit_to_usermode+0x291/0x3b0 [ 25.315651] ? perf_trace_sys_enter+0xb10/0xb10 [ 25.320331] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.325175] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.330383] RIP: 0033:0x4419e9 [ 25.333562] 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 [ 25.352739] RSP: 002b:00007ffffbe2a0b8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 25.360617] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419e9 [ 25.367879] RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 [ 25.375140] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 25.382400] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 25.389659] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 25.396931] [ 25.398567] Allocated by task 4472: [ 25.402199] save_stack+0x43/0xd0 [ 25.405649] kasan_kmalloc+0xc4/0xe0 [ 25.409350] __kmalloc_node+0x47/0x70 [ 25.413139] kvmalloc_node+0x65/0xf0 [ 25.416839] mem_cgroup_css_online+0x169/0x3c0 [ 25.421422] online_css+0x10c/0x350 [ 25.425035] cgroup_apply_control_enable+0x777/0xe90 [ 25.430122] cgroup_mkdir+0x88a/0x1170 [ 25.433996] kernfs_iop_mkdir+0x159/0x1e0 [ 25.438128] vfs_mkdir+0x42e/0x6b0 [ 25.441671] do_mkdirat+0x27b/0x310 [ 25.445283] __x64_sys_mkdir+0x5c/0x80 [ 25.449189] do_syscall_64+0x1b9/0x820 [ 25.453068] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.458237] [ 25.459870] Freed by task 2894: [ 25.463142] save_stack+0x43/0xd0 [ 25.466581] __kasan_slab_free+0x11a/0x170 [ 25.470801] kasan_slab_free+0xe/0x10 [ 25.474585] kfree+0xd9/0x260 [ 25.477690] single_release+0x8f/0xb0 [ 25.481477] __fput+0x35d/0x930 [ 25.484744] ____fput+0x15/0x20 [ 25.488007] task_work_run+0x1ec/0x2a0 [ 25.491885] exit_to_usermode_loop+0x313/0x370 [ 25.496471] do_syscall_64+0x6be/0x820 [ 25.500360] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.505528] [ 25.507160] The buggy address belongs to the object at ffff8801d7877f40 [ 25.507160] which belongs to the cache kmalloc-32 of size 32 [ 25.519737] The buggy address is located 16 bytes inside of [ 25.519737] 32-byte region [ffff8801d7877f40, ffff8801d7877f60) [ 25.531423] The buggy address belongs to the page: [ 25.536343] page:ffffea00075e1dc0 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801d7877fc1 [ 25.545777] flags: 0x2fffc0000000100(slab) [ 25.550001] raw: 02fffc0000000100 ffffea00075d6a48 ffffea00075d2f88 ffff8801da8001c0 [ 25.557885] raw: ffff8801d7877fc1 ffff8801d7877000 000000010000003e 0000000000000000 [ 25.565753] page dumped because: kasan: bad access detected [ 25.571446] [ 25.573059] Memory state around the buggy address: [ 25.577980] ffff8801d7877e00: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc [ 25.585343] ffff8801d7877e80: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc [ 25.592707] >ffff8801d7877f00: 00 00 00 fc fc fc fc fc 00 00 05 fc fc fc fc fc [ 25.600318] ^ [ 25.606280] ffff8801d7877f80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc [ 25.613631] ffff8801d7878000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 25.620973] ================================================================== [ 25.628443] Kernel panic - not syncing: panic_on_warn set ... [ 25.628443] [ 25.635819] CPU: 0 PID: 4473 Comm: syz-executor337 Tainted: G B 4.18.0-rc3-next-20180706+ #1 [ 25.645685] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.655048] Call Trace: [ 25.657636] dump_stack+0x1c9/0x2b4 [ 25.661270] ? dump_stack_print_info.cold.2+0x52/0x52 [ 25.666461] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 25.671208] panic+0x238/0x4e7 [ 25.674386] ? add_taint.cold.5+0x16/0x16 [ 25.678522] ? do_raw_spin_unlock+0xa7/0x2f0 [ 25.682940] ? find_first_bit+0xf7/0x100 [ 25.686999] kasan_end_report+0x47/0x4f [ 25.690967] kasan_report.cold.7+0x76/0x30d [ 25.695291] __asan_report_load8_noabort+0x14/0x20 [ 25.700210] find_first_bit+0xf7/0x100 [ 25.704087] shrink_slab+0x5d0/0xdb0 [ 25.707818] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.713349] ? unregister_memcg_shrinker.isra.39+0x50/0x50 [ 25.718977] ? shrink_active_list+0x1830/0x1830 [ 25.723780] ? save_stack+0xa9/0xd0 [ 25.727408] ? save_stack+0x43/0xd0 [ 25.731032] ? kernfs_fop_open+0xa7f/0x1020 [ 25.735339] ? do_dentry_open+0xa7d/0x11c0 [ 25.739562] ? trace_hardirqs_on+0x10/0x10 [ 25.743817] shrink_node+0x429/0x16a0 [ 25.747614] ? shrink_node_memcg+0x18f0/0x18f0 [ 25.752213] ? kvm_clock_read+0x25/0x30 [ 25.756190] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 25.761197] ? ktime_get_raw_ts64+0x4f0/0x4f0 [ 25.765682] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 25.770714] do_try_to_free_pages+0x3e7/0x1290 [ 25.775315] ? shrink_node+0x16a0/0x16a0 [ 25.779375] ? check_same_owner+0x340/0x340 [ 25.783700] ? trace_hardirqs_on+0x10/0x10 [ 25.787935] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 25.793488] ? _parse_integer+0x13b/0x190 [ 25.797625] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.803972] try_to_free_mem_cgroup_pages+0x49d/0xc90 [ 25.809156] ? pointer_string+0x1b0/0x1b0 [ 25.813327] ? try_to_free_pages+0xb80/0xb80 [ 25.817727] ? memparse+0x171/0x1d0 [ 25.821353] ? get_options+0x380/0x380 [ 25.825230] ? kasan_kmalloc+0xc4/0xe0 [ 25.829104] ? __kmalloc+0x14e/0x760 [ 25.832816] ? kernfs_fop_write+0x33d/0x480 [ 25.837126] ? __vfs_write+0x117/0x9f0 [ 25.841013] ? vfs_write+0x1fc/0x560 [ 25.844720] ? ksys_write+0x101/0x260 [ 25.848527] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 25.854064] ? page_counter_memparse+0xb5/0x1e0 [ 25.858725] ? page_counter_set_low+0x180/0x180 [ 25.863382] ? cgroup_control+0x180/0x180 [ 25.867538] memory_high_write+0x283/0x310 [ 25.871769] ? mem_cgroup_css_released+0x140/0x140 [ 25.876691] ? lock_acquire+0x1e4/0x540 [ 25.880656] ? __might_fault+0x12b/0x1e0 [ 25.884710] cgroup_file_write+0x31f/0x840 [ 25.888937] ? mem_cgroup_css_released+0x140/0x140 [ 25.893871] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 25.898798] ? cgroup_migrate_add_task+0xcd0/0xcd0 [ 25.903726] kernfs_fop_write+0x2ba/0x480 [ 25.907870] __vfs_write+0x117/0x9f0 [ 25.911576] ? kernfs_fop_open+0x1020/0x1020 [ 25.915980] ? kernel_read+0x120/0x120 [ 25.919870] ? lock_release+0xa30/0xa30 [ 25.923836] ? check_same_owner+0x340/0x340 [ 25.928147] ? rcu_note_context_switch+0x730/0x730 [ 25.933070] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 25.938612] ? __sb_start_write+0x17f/0x300 [ 25.943012] vfs_write+0x1fc/0x560 [ 25.946548] ksys_write+0x101/0x260 [ 25.950179] ? __ia32_sys_read+0xb0/0xb0 [ 25.954233] __x64_sys_write+0x73/0xb0 [ 25.958113] do_syscall_64+0x1b9/0x820 [ 25.961988] ? syscall_return_slowpath+0x5e0/0x5e0 [ 25.966923] ? syscall_return_slowpath+0x31d/0x5e0 [ 25.971860] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 25.976876] ? prepare_exit_to_usermode+0x291/0x3b0 [ 25.981894] ? perf_trace_sys_enter+0xb10/0xb10 [ 25.986581] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 25.991416] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 25.996597] RIP: 0033:0x4419e9 [ 25.999779] 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 [ 26.019109] RSP: 002b:00007ffffbe2a0b8 EFLAGS: 00000217 ORIG_RAX: 0000000000000001 [ 26.026821] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004419e9 [ 26.034079] RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000004 [ 26.041341] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 [ 26.048608] R10: 0000000000000006 R11: 0000000000000217 R12: 0000000000000000 [ 26.055891] R13: 6c616b7a79732f2e R14: 0000000000000000 R15: 0000000000000000 [ 26.063822] Dumping ftrace buffer: [ 26.067362] (ftrace buffer empty) [ 26.071058] Kernel Offset: disabled [ 26.074695] Rebooting in 86400 seconds..