[ 27.928745] kauditd_printk_skb: 7 callbacks suppressed [ 27.928759] audit: type=1800 audit(1541517863.568:28): pid=5562 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2417 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 28.801010] audit: type=1800 audit(1541517864.438:29): pid=5562 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.819999] audit: type=1800 audit(1541517864.438:30): pid=5562 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 '10.128.0.19' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 59.703290] ================================================================== [ 59.710845] BUG: KASAN: use-after-free in vb2_mmap+0x662/0x6f0 [ 59.716870] Read of size 8 at addr ffff8801ce7f44c0 by task syz-executor209/5731 [ 59.724392] [ 59.726024] CPU: 0 PID: 5731 Comm: syz-executor209 Not tainted 4.20.0-rc1+ #100 [ 59.733465] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.742810] Call Trace: [ 59.745396] dump_stack+0x244/0x39d [ 59.749026] ? dump_stack_print_info.cold.1+0x20/0x20 [ 59.754206] ? printk+0xa7/0xcf [ 59.757479] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 59.762224] print_address_description.cold.7+0x9/0x1ff [ 59.767574] kasan_report.cold.8+0x242/0x309 [ 59.771973] ? vb2_mmap+0x662/0x6f0 [ 59.775636] __asan_report_load8_noabort+0x14/0x20 [ 59.780560] vb2_mmap+0x662/0x6f0 [ 59.784003] ? vb2_poll+0x1d0/0x1d0 [ 59.787621] vb2_fop_mmap+0x4b/0x70 [ 59.791238] v4l2_mmap+0x153/0x200 [ 59.794834] mmap_region+0xe85/0x1cd0 [ 59.798647] ? __x64_sys_brk+0x8b0/0x8b0 [ 59.802699] ? smack_task_getsecid+0x1e6/0x3c0 [ 59.807384] ? lock_downgrade+0x900/0x900 [ 59.811529] ? check_preemption_disabled+0x48/0x280 [ 59.816827] ? rcu_read_unlock_special+0x1c0/0x1c0 [ 59.821792] ? kasan_check_read+0x11/0x20 [ 59.825934] ? mpx_unmapped_area_check+0xd8/0x108 [ 59.830770] ? arch_get_unmapped_area+0x750/0x750 [ 59.835601] ? lock_acquire+0x1ed/0x520 [ 59.839565] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 59.844573] ? cap_mmap_addr+0x52/0x130 [ 59.848604] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 59.854151] ? security_mmap_addr+0x80/0xa0 [ 59.858471] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 59.864003] ? get_unmapped_area+0x292/0x3b0 [ 59.868400] do_mmap+0xa22/0x1230 [ 59.871853] ? mmap_region+0x1cd0/0x1cd0 [ 59.875906] ? vm_mmap_pgoff+0x1b5/0x2c0 [ 59.879957] ? down_read_killable+0x150/0x150 [ 59.884462] ? security_mmap_file+0x174/0x1b0 [ 59.888965] vm_mmap_pgoff+0x213/0x2c0 [ 59.892850] ? vma_is_stack_for_current+0xd0/0xd0 [ 59.897681] ? putname+0xf2/0x130 [ 59.901123] ? rcu_read_lock_sched_held+0x14f/0x180 [ 59.906138] ksys_mmap_pgoff+0x4da/0x660 [ 59.910195] ? do_syscall_64+0x9a/0x820 [ 59.914247] ? find_mergeable_anon_vma+0xd0/0xd0 [ 59.919104] ? trace_hardirqs_on+0xbd/0x310 [ 59.923425] ? filp_open+0x80/0x80 [ 59.926955] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 59.932499] ? trace_hardirqs_off_caller+0x310/0x310 [ 59.937596] __x64_sys_mmap+0xe9/0x1b0 [ 59.941477] do_syscall_64+0x1b9/0x820 [ 59.945352] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 59.950706] ? syscall_return_slowpath+0x5e0/0x5e0 [ 59.955673] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 59.960514] ? trace_hardirqs_on_caller+0x310/0x310 [ 59.965523] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 59.970596] ? prepare_exit_to_usermode+0x291/0x3b0 [ 59.975609] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 59.980454] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 59.985730] RIP: 0033:0x444bf9 [ 59.988912] 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 [ 60.007805] RSP: 002b:00007fffa44a64d8 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 [ 60.015506] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444bf9 [ 60.022763] RDX: 000000000000000d RSI: 0000000000002000 RDI: 0000000020ffe000 [ 60.030020] RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000 [ 60.037279] R10: 0000000000080851 R11: 0000000000000216 R12: 000000000000e882 [ 60.044537] R13: 0000000000401f40 R14: 0000000000000000 R15: 0000000000000000 [ 60.051798] [ 60.053408] Allocated by task 5733: [ 60.057129] save_stack+0x43/0xd0 [ 60.060573] kasan_kmalloc+0xc7/0xe0 [ 60.064272] __kmalloc+0x15b/0x760 [ 60.067801] __vb2_queue_alloc+0xf7/0xf90 [ 60.071981] vb2_core_reqbufs+0x971/0x1040 [ 60.076213] vb2_ioctl_reqbufs+0x1f5/0x3a0 [ 60.080443] v4l_reqbufs+0xae/0xd0 [ 60.083974] __video_do_ioctl+0x8b1/0x1050 [ 60.088258] video_usercopy+0x5c1/0x1760 [ 60.092308] video_ioctl2+0x2c/0x33 [ 60.095920] v4l2_ioctl+0x154/0x1b0 [ 60.099532] do_vfs_ioctl+0x1de/0x1790 [ 60.103400] ksys_ioctl+0xa9/0xd0 [ 60.106850] __x64_sys_ioctl+0x73/0xb0 [ 60.110726] do_syscall_64+0x1b9/0x820 [ 60.114659] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.119834] [ 60.121444] Freed by task 5733: [ 60.124714] save_stack+0x43/0xd0 [ 60.128153] __kasan_slab_free+0x102/0x150 [ 60.132373] kasan_slab_free+0xe/0x10 [ 60.136157] kfree+0xcf/0x230 [ 60.139246] __vb2_queue_free+0x5e2/0xa30 [ 60.143377] vb2_core_queue_release+0x62/0x80 [ 60.147854] _vb2_fop_release+0x1d2/0x2b0 [ 60.151987] vb2_fop_release+0x77/0xc0 [ 60.155857] v4l2_release+0x2f2/0x3a0 [ 60.159641] __fput+0x385/0xa30 [ 60.162902] ____fput+0x15/0x20 [ 60.166164] task_work_run+0x1e8/0x2a0 [ 60.170037] exit_to_usermode_loop+0x318/0x380 [ 60.174602] do_syscall_64+0x6be/0x820 [ 60.178483] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.183649] [ 60.185262] The buggy address belongs to the object at ffff8801ce7f44c0 [ 60.185262] which belongs to the cache kmalloc-1k of size 1024 [ 60.197903] The buggy address is located 0 bytes inside of [ 60.197903] 1024-byte region [ffff8801ce7f44c0, ffff8801ce7f48c0) [ 60.209670] The buggy address belongs to the page: [ 60.214581] page:ffffea000739fd00 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0 compound_mapcount: 0 [ 60.224533] flags: 0x2fffc0000010200(slab|head) [ 60.229189] raw: 02fffc0000010200 ffffea00070b2488 ffffea0006f06908 ffff8801da800ac0 [ 60.237102] raw: 0000000000000000 ffff8801ce7f4040 0000000100000007 0000000000000000 [ 60.244970] page dumped because: kasan: bad access detected [ 60.250662] [ 60.252268] Memory state around the buggy address: [ 60.257179] ffff8801ce7f4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.264518] ffff8801ce7f4400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 60.271860] >ffff8801ce7f4480: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 60.279197] ^ [ 60.284630] ffff8801ce7f4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.292031] ffff8801ce7f4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.299380] ================================================================== [ 60.306719] Disabling lock debugging due to kernel taint [ 60.313240] Kernel panic - not syncing: panic_on_warn set ... [ 60.319122] CPU: 0 PID: 5731 Comm: syz-executor209 Tainted: G B 4.20.0-rc1+ #100 [ 60.327941] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.337280] Call Trace: [ 60.339857] dump_stack+0x244/0x39d [ 60.343570] ? dump_stack_print_info.cold.1+0x20/0x20 [ 60.348768] panic+0x2ad/0x55c [ 60.351948] ? add_taint.cold.5+0x16/0x16 [ 60.356082] ? preempt_schedule+0x4d/0x60 [ 60.360315] ? ___preempt_schedule+0x16/0x18 [ 60.364711] ? trace_hardirqs_on+0xb4/0x310 [ 60.369018] kasan_end_report+0x47/0x4f [ 60.372974] kasan_report.cold.8+0x76/0x309 [ 60.377282] ? vb2_mmap+0x662/0x6f0 [ 60.380892] __asan_report_load8_noabort+0x14/0x20 [ 60.385802] vb2_mmap+0x662/0x6f0 [ 60.389239] ? vb2_poll+0x1d0/0x1d0 [ 60.392847] vb2_fop_mmap+0x4b/0x70 [ 60.396458] v4l2_mmap+0x153/0x200 [ 60.399988] mmap_region+0xe85/0x1cd0 [ 60.403775] ? __x64_sys_brk+0x8b0/0x8b0 [ 60.407820] ? smack_task_getsecid+0x1e6/0x3c0 [ 60.412385] ? lock_downgrade+0x900/0x900 [ 60.416517] ? check_preemption_disabled+0x48/0x280 [ 60.421566] ? rcu_read_unlock_special+0x1c0/0x1c0 [ 60.426531] ? kasan_check_read+0x11/0x20 [ 60.430683] ? mpx_unmapped_area_check+0xd8/0x108 [ 60.435524] ? arch_get_unmapped_area+0x750/0x750 [ 60.440351] ? lock_acquire+0x1ed/0x520 [ 60.444313] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 60.449436] ? cap_mmap_addr+0x52/0x130 [ 60.453532] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 60.459055] ? security_mmap_addr+0x80/0xa0 [ 60.463361] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 60.468882] ? get_unmapped_area+0x292/0x3b0 [ 60.473273] do_mmap+0xa22/0x1230 [ 60.476716] ? mmap_region+0x1cd0/0x1cd0 [ 60.480762] ? vm_mmap_pgoff+0x1b5/0x2c0 [ 60.484811] ? down_read_killable+0x150/0x150 [ 60.489287] ? security_mmap_file+0x174/0x1b0 [ 60.493766] vm_mmap_pgoff+0x213/0x2c0 [ 60.497640] ? vma_is_stack_for_current+0xd0/0xd0 [ 60.502469] ? putname+0xf2/0x130 [ 60.505907] ? rcu_read_lock_sched_held+0x14f/0x180 [ 60.510910] ksys_mmap_pgoff+0x4da/0x660 [ 60.514956] ? do_syscall_64+0x9a/0x820 [ 60.518914] ? find_mergeable_anon_vma+0xd0/0xd0 [ 60.523799] ? trace_hardirqs_on+0xbd/0x310 [ 60.528106] ? filp_open+0x80/0x80 [ 60.531636] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.537045] ? trace_hardirqs_off_caller+0x310/0x310 [ 60.542146] __x64_sys_mmap+0xe9/0x1b0 [ 60.546021] do_syscall_64+0x1b9/0x820 [ 60.549896] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 60.555246] ? syscall_return_slowpath+0x5e0/0x5e0 [ 60.560164] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 60.565001] ? trace_hardirqs_on_caller+0x310/0x310 [ 60.570007] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 60.575013] ? prepare_exit_to_usermode+0x291/0x3b0 [ 60.580017] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 60.584856] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 60.590035] RIP: 0033:0x444bf9 [ 60.593210] 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 [ 60.612098] RSP: 002b:00007fffa44a64d8 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 [ 60.619791] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444bf9 [ 60.627044] RDX: 000000000000000d RSI: 0000000000002000 RDI: 0000000020ffe000 [ 60.634293] RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000 [ 60.641610] R10: 0000000000080851 R11: 0000000000000216 R12: 000000000000e882 [ 60.648868] R13: 0000000000401f40 R14: 0000000000000000 R15: 0000000000000000 [ 60.657072] Kernel Offset: disabled [ 60.660694] Rebooting in 86400 seconds..