[....] 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[?25l[?1c7[ ok 8[?25h[?0c. [ 27.854728] kauditd_printk_skb: 7 callbacks suppressed [ 27.854740] audit: type=1800 audit(1541519405.085:29): pid=5560 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 27.880560] audit: type=1800 audit(1541519405.085:30): pid=5560 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.0' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 39.738803] ================================================================== [ 39.746373] BUG: KASAN: use-after-free in vb2_mmap+0x662/0x6f0 [ 39.752335] Read of size 8 at addr ffff8801d37f2dc0 by task syz-executor598/5724 [ 39.759850] [ 39.761470] CPU: 1 PID: 5724 Comm: syz-executor598 Not tainted 4.20.0-rc1+ #100 [ 39.768899] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.778238] Call Trace: [ 39.780831] dump_stack+0x244/0x39d [ 39.784456] ? dump_stack_print_info.cold.1+0x20/0x20 [ 39.789636] ? printk+0xa7/0xcf [ 39.792909] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 39.797664] print_address_description.cold.7+0x9/0x1ff [ 39.803018] kasan_report.cold.8+0x242/0x309 [ 39.807414] ? vb2_mmap+0x662/0x6f0 [ 39.811146] __asan_report_load8_noabort+0x14/0x20 [ 39.816252] vb2_mmap+0x662/0x6f0 [ 39.819709] ? vb2_poll+0x1d0/0x1d0 [ 39.823329] vb2_fop_mmap+0x4b/0x70 [ 39.826943] v4l2_mmap+0x153/0x200 [ 39.830474] mmap_region+0xe85/0x1cd0 [ 39.834268] ? __x64_sys_brk+0x8b0/0x8b0 [ 39.838319] ? zap_class+0x640/0x640 [ 39.842026] ? mpx_unmapped_area_check+0xd8/0x108 [ 39.846881] ? arch_get_unmapped_area+0x750/0x750 [ 39.851726] ? lock_acquire+0x1ed/0x520 [ 39.855689] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 39.860692] ? cap_mmap_addr+0x52/0x130 [ 39.864654] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 39.870181] ? security_mmap_addr+0x80/0xa0 [ 39.874589] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 39.880143] ? get_unmapped_area+0x292/0x3b0 [ 39.884545] do_mmap+0xa22/0x1230 [ 39.887995] ? mmap_region+0x1cd0/0x1cd0 [ 39.892045] ? vm_mmap_pgoff+0x1b5/0x2c0 [ 39.896099] ? down_read_killable+0x150/0x150 [ 39.900585] ? security_mmap_file+0x174/0x1b0 [ 39.905072] vm_mmap_pgoff+0x213/0x2c0 [ 39.908976] ? vma_is_stack_for_current+0xd0/0xd0 [ 39.913834] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 39.919377] ? security_file_permission+0x1c2/0x220 [ 39.924400] ksys_mmap_pgoff+0x4da/0x660 [ 39.928467] ? do_syscall_64+0x9a/0x820 [ 39.932460] ? find_mergeable_anon_vma+0xd0/0xd0 [ 39.937204] ? trace_hardirqs_on+0xbd/0x310 [ 39.941517] ? __ia32_sys_read+0xb0/0xb0 [ 39.945571] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 39.950922] ? trace_hardirqs_off_caller+0x310/0x310 [ 39.956018] __x64_sys_mmap+0xe9/0x1b0 [ 39.959898] do_syscall_64+0x1b9/0x820 [ 39.963778] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 39.969139] ? syscall_return_slowpath+0x5e0/0x5e0 [ 39.974062] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.978908] ? trace_hardirqs_on_caller+0x310/0x310 [ 39.983915] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 39.988919] ? prepare_exit_to_usermode+0x291/0x3b0 [ 39.993935] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.998786] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.003969] RIP: 0033:0x444b89 [ 40.007151] Code: e8 ac e8 ff ff 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 2b ce fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 40.026042] RSP: 002b:00007ffcf03c2e08 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 [ 40.033743] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444b89 [ 40.040998] RDX: 0000000000000003 RSI: 0000000000003000 RDI: 0000000020ffd000 [ 40.048254] RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 [ 40.055511] R10: 0000000000000011 R11: 0000000000000216 R12: 0000000000401e40 [ 40.062768] R13: 0000000000401ed0 R14: 0000000000000000 R15: 0000000000000000 [ 40.070031] [ 40.071645] Allocated by task 5719: [ 40.075262] save_stack+0x43/0xd0 [ 40.078702] kasan_kmalloc+0xc7/0xe0 [ 40.082400] __kmalloc+0x15b/0x760 [ 40.085937] __vb2_queue_alloc+0xf7/0xf90 [ 40.090074] vb2_core_reqbufs+0x971/0x1040 [ 40.094293] __vb2_init_fileio+0x344/0xc90 [ 40.098526] __vb2_perform_fileio+0xcfd/0x1210 [ 40.103119] vb2_write+0x38/0x50 [ 40.106498] vb2_fop_write+0x20a/0x400 [ 40.110409] v4l2_write+0x168/0x220 [ 40.114144] __vfs_write+0x119/0x9f0 [ 40.117856] vfs_write+0x1fc/0x560 [ 40.121406] ksys_write+0x101/0x260 [ 40.125086] __x64_sys_write+0x73/0xb0 [ 40.128969] do_syscall_64+0x1b9/0x820 [ 40.132854] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.138048] [ 40.139671] Freed by task 5719: [ 40.142956] save_stack+0x43/0xd0 [ 40.146406] __kasan_slab_free+0x102/0x150 [ 40.150653] kasan_slab_free+0xe/0x10 [ 40.154457] kfree+0xcf/0x230 [ 40.157566] __vb2_queue_free+0x5e2/0xa30 [ 40.161703] vb2_core_reqbufs+0x2da/0x1040 [ 40.166048] __vb2_cleanup_fileio+0xf0/0x160 [ 40.170456] vb2_core_queue_release+0x1e/0x80 [ 40.174938] _vb2_fop_release+0x1d2/0x2b0 [ 40.179073] vb2_fop_release+0x77/0xc0 [ 40.183044] vivid_fop_release+0x18e/0x440 [ 40.187286] v4l2_release+0x224/0x3a0 [ 40.191081] __fput+0x385/0xa30 [ 40.194370] ____fput+0x15/0x20 [ 40.197651] task_work_run+0x1e8/0x2a0 [ 40.201539] exit_to_usermode_loop+0x318/0x380 [ 40.206112] do_syscall_64+0x6be/0x820 [ 40.210061] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.215232] [ 40.216850] The buggy address belongs to the object at ffff8801d37f2dc0 [ 40.216850] which belongs to the cache kmalloc-1k of size 1024 [ 40.229498] The buggy address is located 0 bytes inside of [ 40.229498] 1024-byte region [ffff8801d37f2dc0, ffff8801d37f31c0) [ 40.241277] The buggy address belongs to the page: [ 40.246197] page:ffffea00074dfc80 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0 compound_mapcount: 0 [ 40.256151] flags: 0x2fffc0000010200(slab|head) [ 40.260812] raw: 02fffc0000010200 ffffea00074d7308 ffffea00074c1a88 ffff8801da800ac0 [ 40.268684] raw: 0000000000000000 ffff8801d37f2040 0000000100000007 0000000000000000 [ 40.276547] page dumped because: kasan: bad access detected [ 40.282249] [ 40.283858] Memory state around the buggy address: [ 40.289123] ffff8801d37f2c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.296473] ffff8801d37f2d00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 40.303821] >ffff8801d37f2d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 40.311162] ^ [ 40.316735] ffff8801d37f2e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.324084] ffff8801d37f2e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.331439] ================================================================== [ 40.338795] Disabling lock debugging due to kernel taint [ 40.344415] Kernel panic - not syncing: panic_on_warn set ... [ 40.350349] CPU: 1 PID: 5724 Comm: syz-executor598 Tainted: G B 4.20.0-rc1+ #100 [ 40.359190] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.368539] Call Trace: [ 40.371148] dump_stack+0x244/0x39d [ 40.374769] ? dump_stack_print_info.cold.1+0x20/0x20 [ 40.379952] panic+0x2ad/0x55c [ 40.383137] ? add_taint.cold.5+0x16/0x16 [ 40.387272] ? preempt_schedule+0x4d/0x60 [ 40.391409] ? ___preempt_schedule+0x16/0x18 [ 40.395815] ? trace_hardirqs_on+0xb4/0x310 [ 40.400129] kasan_end_report+0x47/0x4f [ 40.404092] kasan_report.cold.8+0x76/0x309 [ 40.408409] ? vb2_mmap+0x662/0x6f0 [ 40.412094] __asan_report_load8_noabort+0x14/0x20 [ 40.417025] vb2_mmap+0x662/0x6f0 [ 40.420469] ? vb2_poll+0x1d0/0x1d0 [ 40.424084] vb2_fop_mmap+0x4b/0x70 [ 40.427708] v4l2_mmap+0x153/0x200 [ 40.431251] mmap_region+0xe85/0x1cd0 [ 40.435048] ? __x64_sys_brk+0x8b0/0x8b0 [ 40.439102] ? zap_class+0x640/0x640 [ 40.442806] ? mpx_unmapped_area_check+0xd8/0x108 [ 40.447675] ? arch_get_unmapped_area+0x750/0x750 [ 40.452706] ? lock_acquire+0x1ed/0x520 [ 40.456668] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 40.461673] ? cap_mmap_addr+0x52/0x130 [ 40.465635] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.471267] ? security_mmap_addr+0x80/0xa0 [ 40.475578] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.481106] ? get_unmapped_area+0x292/0x3b0 [ 40.485505] do_mmap+0xa22/0x1230 [ 40.488968] ? mmap_region+0x1cd0/0x1cd0 [ 40.493019] ? vm_mmap_pgoff+0x1b5/0x2c0 [ 40.497068] ? down_read_killable+0x150/0x150 [ 40.501550] ? security_mmap_file+0x174/0x1b0 [ 40.506034] vm_mmap_pgoff+0x213/0x2c0 [ 40.509912] ? vma_is_stack_for_current+0xd0/0xd0 [ 40.514868] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.520396] ? security_file_permission+0x1c2/0x220 [ 40.525405] ksys_mmap_pgoff+0x4da/0x660 [ 40.529547] ? do_syscall_64+0x9a/0x820 [ 40.533587] ? find_mergeable_anon_vma+0xd0/0xd0 [ 40.538334] ? trace_hardirqs_on+0xbd/0x310 [ 40.542647] ? __ia32_sys_read+0xb0/0xb0 [ 40.546700] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.549002] kobject: 'regulatory.0' (00000000af80be75): kobject_uevent_env [ 40.552064] ? trace_hardirqs_off_caller+0x310/0x310 [ 40.559250] kobject: 'regulatory.0' (00000000af80be75): fill_kobj_path: path = '/devices/platform/regulatory.0' [ 40.564188] __x64_sys_mmap+0xe9/0x1b0 [ 40.564207] do_syscall_64+0x1b9/0x820 [ 40.564229] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.587549] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.592466] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.597367] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.602381] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.607388] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.612396] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.617248] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.622443] RIP: 0033:0x444b89 [ 40.625627] Code: e8 ac e8 ff ff 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 2b ce fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 40.644516] RSP: 002b:00007ffcf03c2e08 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 [ 40.652209] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444b89 [ 40.659465] RDX: 0000000000000003 RSI: 0000000000003000 RDI: 0000000020ffd000 [ 40.666720] RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 [ 40.673973] R10: 0000000000000011 R11: 0000000000000216 R12: 0000000000401e40 [ 40.681276] R13: 0000000000401ed0 R14: 0000000000000000 R15: 0000000000000000 [ 40.689571] Kernel Offset: disabled [ 40.693198] Rebooting in 86400 seconds..