[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 43.837735][ T27] audit: type=1800 audit(1556643024.250:25): pid=7842 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 43.865385][ T27] audit: type=1800 audit(1556643024.250:26): pid=7842 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 43.898068][ T27] audit: type=1800 audit(1556643024.250:27): pid=7842 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.9' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 54.943665][ T8098] ================================================================== [ 54.951892][ T8098] BUG: KASAN: use-after-free in __vb2_perform_fileio+0x1065/0x1140 [ 54.959774][ T8098] Read of size 4 at addr ffff88809031479c by task syz-executor048/8098 [ 54.967991][ T8098] [ 54.970311][ T8098] CPU: 0 PID: 8098 Comm: syz-executor048 Not tainted 5.1.0-rc7+ #92 [ 54.978260][ T8098] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.988314][ T8098] Call Trace: [ 54.991687][ T8098] dump_stack+0x172/0x1f0 [ 54.996002][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.001552][ T8098] print_address_description.cold+0x7c/0x20d [ 55.007542][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.013069][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.018598][ T8098] kasan_report.cold+0x1b/0x40 [ 55.023365][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.028900][ T8098] __asan_report_load4_noabort+0x14/0x20 [ 55.034514][ T8098] __vb2_perform_fileio+0x1065/0x1140 [ 55.039882][ T8098] ? aa_path_link+0x460/0x460 [ 55.044542][ T8098] ? vb2_thread_start+0x370/0x370 [ 55.049561][ T8098] vb2_read+0x3b/0x50 [ 55.053532][ T8098] vb2_fop_read+0x212/0x410 [ 55.058024][ T8098] ? vb2_fop_write+0x410/0x410 [ 55.062778][ T8098] v4l2_read+0x1ce/0x230 [ 55.067010][ T8098] __vfs_read+0x8d/0x110 [ 55.071240][ T8098] ? v4l2_write+0x230/0x230 [ 55.075757][ T8098] vfs_read+0x194/0x3e0 [ 55.079911][ T8098] ksys_read+0x14f/0x2d0 [ 55.084144][ T8098] ? kernel_write+0x120/0x120 [ 55.088803][ T8098] ? do_fast_syscall_32+0xd1/0xc98 [ 55.093896][ T8098] ? entry_SYSENTER_compat+0x70/0x7f [ 55.099167][ T8098] ? do_fast_syscall_32+0xd1/0xc98 [ 55.104261][ T8098] __ia32_sys_read+0x71/0xb0 [ 55.108842][ T8098] do_fast_syscall_32+0x281/0xc98 [ 55.113850][ T8098] entry_SYSENTER_compat+0x70/0x7f [ 55.118939][ T8098] RIP: 0023:0xf7f5d869 [ 55.122989][ T8098] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 55.142599][ T8098] RSP: 002b:00000000ff94a4bc EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 55.150999][ T8098] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000180 [ 55.158966][ T8098] RDX: 0000000000000052 RSI: 0000000000000001 RDI: 00000000ff94a5d4 [ 55.166918][ T8098] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 55.174993][ T8098] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 55.182965][ T8098] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 55.190928][ T8098] [ 55.193247][ T8098] Allocated by task 8097: [ 55.197566][ T8098] save_stack+0x45/0xd0 [ 55.201711][ T8098] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 55.207365][ T8098] kasan_kmalloc+0x9/0x10 [ 55.211676][ T8098] kmem_cache_alloc_trace+0x151/0x760 [ 55.217033][ T8098] __vb2_init_fileio+0x1cb/0xbe0 [ 55.221951][ T8098] __vb2_perform_fileio+0xc01/0x1140 [ 55.227221][ T8098] vb2_read+0x3b/0x50 [ 55.231201][ T8098] vb2_fop_read+0x212/0x410 [ 55.235681][ T8098] v4l2_read+0x1ce/0x230 [ 55.239905][ T8098] __vfs_read+0x8d/0x110 [ 55.244127][ T8098] vfs_read+0x194/0x3e0 [ 55.248261][ T8098] ksys_read+0x14f/0x2d0 [ 55.252487][ T8098] __ia32_sys_read+0x71/0xb0 [ 55.257063][ T8098] do_fast_syscall_32+0x281/0xc98 [ 55.262075][ T8098] entry_SYSENTER_compat+0x70/0x7f [ 55.267274][ T8098] [ 55.269598][ T8098] Freed by task 8099: [ 55.273594][ T8098] save_stack+0x45/0xd0 [ 55.277762][ T8098] __kasan_slab_free+0x102/0x150 [ 55.282683][ T8098] kasan_slab_free+0xe/0x10 [ 55.287167][ T8098] kfree+0xcf/0x230 [ 55.290957][ T8098] __vb2_cleanup_fileio+0x100/0x170 [ 55.296146][ T8098] vb2_core_queue_release+0x20/0x80 [ 55.301363][ T8098] _vb2_fop_release+0x1cf/0x2a0 [ 55.306294][ T8098] vb2_fop_release+0x75/0xc0 [ 55.310867][ T8098] vivid_fop_release+0x18e/0x430 [ 55.315786][ T8098] v4l2_release+0x224/0x3a0 [ 55.320369][ T8098] __fput+0x2e5/0x8d0 [ 55.325808][ T8098] ____fput+0x16/0x20 [ 55.329772][ T8098] task_work_run+0x14a/0x1c0 [ 55.334346][ T8098] do_exit+0x90a/0x2fa0 [ 55.338497][ T8098] do_group_exit+0x135/0x370 [ 55.343068][ T8098] __ia32_sys_exit_group+0x44/0x50 [ 55.348178][ T8098] do_fast_syscall_32+0x281/0xc98 [ 55.353184][ T8098] entry_SYSENTER_compat+0x70/0x7f [ 55.358293][ T8098] [ 55.360617][ T8098] The buggy address belongs to the object at ffff888090314480 [ 55.360617][ T8098] which belongs to the cache kmalloc-1k of size 1024 [ 55.374672][ T8098] The buggy address is located 796 bytes inside of [ 55.374672][ T8098] 1024-byte region [ffff888090314480, ffff888090314880) [ 55.388006][ T8098] The buggy address belongs to the page: [ 55.393628][ T8098] page:ffffea000240c500 count:1 mapcount:0 mapping:ffff8880aa400ac0 index:0x0 compound_mapcount: 0 [ 55.404290][ T8098] flags: 0x1fffc0000010200(slab|head) [ 55.409648][ T8098] raw: 01fffc0000010200 ffffea00029e5788 ffffea00029eba08 ffff8880aa400ac0 [ 55.418215][ T8098] raw: 0000000000000000 ffff888090314000 0000000100000007 0000000000000000 [ 55.426775][ T8098] page dumped because: kasan: bad access detected [ 55.433168][ T8098] [ 55.435471][ T8098] Memory state around the buggy address: [ 55.441080][ T8098] ffff888090314680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.449123][ T8098] ffff888090314700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.457169][ T8098] >ffff888090314780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.465205][ T8098] ^ [ 55.470035][ T8098] ffff888090314800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.478078][ T8098] ffff888090314880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 55.486120][ T8098] ================================================================== [ 55.494876][ T8098] Disabling lock debugging due to kernel taint [ 55.502581][ T8098] Kernel panic - not syncing: panic_on_warn set ... [ 55.509210][ T8098] CPU: 1 PID: 8098 Comm: syz-executor048 Tainted: G B 5.1.0-rc7+ #92 [ 55.518593][ T8098] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.528642][ T8098] Call Trace: [ 55.531917][ T8098] dump_stack+0x172/0x1f0 [ 55.536226][ T8098] panic+0x2cb/0x65c [ 55.540102][ T8098] ? __warn_printk+0xf3/0xf3 [ 55.544670][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.550196][ T8098] ? preempt_schedule+0x4b/0x60 [ 55.555026][ T8098] ? ___preempt_schedule+0x16/0x18 [ 55.560115][ T8098] ? trace_hardirqs_on+0x5e/0x230 [ 55.565142][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.570663][ T8098] end_report+0x47/0x4f [ 55.574795][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.580319][ T8098] kasan_report.cold+0xe/0x40 [ 55.584972][ T8098] ? __vb2_perform_fileio+0x1065/0x1140 [ 55.590502][ T8098] __asan_report_load4_noabort+0x14/0x20 [ 55.596128][ T8098] __vb2_perform_fileio+0x1065/0x1140 [ 55.601489][ T8098] ? aa_path_link+0x460/0x460 [ 55.606159][ T8098] ? vb2_thread_start+0x370/0x370 [ 55.611163][ T8098] vb2_read+0x3b/0x50 [ 55.615122][ T8098] vb2_fop_read+0x212/0x410 [ 55.619618][ T8098] ? vb2_fop_write+0x410/0x410 [ 55.624365][ T8098] v4l2_read+0x1ce/0x230 [ 55.628591][ T8098] __vfs_read+0x8d/0x110 [ 55.632812][ T8098] ? v4l2_write+0x230/0x230 [ 55.637302][ T8098] vfs_read+0x194/0x3e0 [ 55.641440][ T8098] ksys_read+0x14f/0x2d0 [ 55.645658][ T8098] ? kernel_write+0x120/0x120 [ 55.650315][ T8098] ? do_fast_syscall_32+0xd1/0xc98 [ 55.655404][ T8098] ? entry_SYSENTER_compat+0x70/0x7f [ 55.660672][ T8098] ? do_fast_syscall_32+0xd1/0xc98 [ 55.665776][ T8098] __ia32_sys_read+0x71/0xb0 [ 55.670370][ T8098] do_fast_syscall_32+0x281/0xc98 [ 55.675380][ T8098] entry_SYSENTER_compat+0x70/0x7f [ 55.680465][ T8098] RIP: 0023:0xf7f5d869 [ 55.684508][ T8098] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 55.704094][ T8098] RSP: 002b:00000000ff94a4bc EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 55.712480][ T8098] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000180 [ 55.720429][ T8098] RDX: 0000000000000052 RSI: 0000000000000001 RDI: 00000000ff94a5d4 [ 55.728376][ T8098] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 55.736320][ T8098] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 55.744303][ T8098] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 55.753273][ T8098] Kernel Offset: disabled [ 55.757596][ T8098] Rebooting in 86400 seconds..