[   24.226430] audit: type=1800 audit(1541307439.268:21): pid=5512 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="bootlogs" dev="sda1" ino=2419 res=0
[   24.254939] audit: type=1800 audit(1541307439.268:22): pid=5512 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="motd" dev="sda1" ino=2447 res=0
[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[   25.208671] sshd (5577) used greatest stack depth: 15232 bytes left
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

Warning: Permanently added '10.128.0.37' (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
syzkaller login: [   45.159256] ==================================================================
[   45.166861] BUG: KASAN: use-after-free in vb2_mmap+0x662/0x6f0
[   45.172832] Read of size 8 at addr ffff8801d743fb00 by task syz-executor400/5681
[   45.180347] 
[   45.181972] CPU: 1 PID: 5681 Comm: syz-executor400 Not tainted 4.19.0+ #221
[   45.189121] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   45.198473] Call Trace:
[   45.201058]  dump_stack+0x244/0x39d
[   45.204673]  ? dump_stack_print_info.cold.1+0x20/0x20
[   45.209847]  ? printk+0xa7/0xcf
[   45.213130]  ? kmsg_dump_rewind_nolock+0xe4/0xe4
[   45.217887]  print_address_description.cold.7+0x9/0x1ff
[   45.223238]  kasan_report.cold.8+0x242/0x309
[   45.227643]  ? vb2_mmap+0x662/0x6f0
[   45.231265]  __asan_report_load8_noabort+0x14/0x20
[   45.236181]  vb2_mmap+0x662/0x6f0
[   45.239624]  ? vb2_poll+0x1d0/0x1d0
[   45.243250]  vb2_fop_mmap+0x4b/0x70
[   45.246873]  v4l2_mmap+0x153/0x200
[   45.250402]  mmap_region+0xe85/0x1cd0
[   45.254207]  ? __x64_sys_brk+0x8b0/0x8b0
[   45.258266]  ? zap_class+0x640/0x640
[   45.261977]  ? __kernel_text_address+0xd/0x40
[   45.266474]  ? mpx_unmapped_area_check+0xd8/0x108
[   45.271328]  ? arch_get_unmapped_area+0x750/0x750
[   45.276174]  ? lock_acquire+0x1ed/0x520
[   45.280149]  ? __sanitizer_cov_trace_cmp8+0x18/0x20
[   45.285163]  ? cap_mmap_addr+0x52/0x130
[   45.289238]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   45.294768]  ? security_mmap_addr+0x80/0xa0
[   45.299081]  ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[   45.304611]  ? get_unmapped_area+0x292/0x3b0
[   45.309009]  do_mmap+0xa22/0x1230
[   45.312461]  ? mmap_region+0x1cd0/0x1cd0
[   45.316506]  ? vm_mmap_pgoff+0x1b5/0x2c0
[   45.320553]  ? down_read_killable+0x150/0x150
[   45.325042]  ? security_mmap_file+0x174/0x1b0
[   45.329525]  vm_mmap_pgoff+0x213/0x2c0
[   45.333406]  ? vma_is_stack_for_current+0xd0/0xd0
[   45.338234]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   45.343758]  ? security_file_permission+0x1c2/0x220
[   45.348769]  ksys_mmap_pgoff+0x4da/0x660
[   45.352814]  ? do_fast_syscall_32+0x150/0xfb2
[   45.357297]  ? find_mergeable_anon_vma+0xd0/0xd0
[   45.362047]  ? trace_hardirqs_on+0xbd/0x310
[   45.366362]  ? __ia32_sys_read+0xb0/0xb0
[   45.370524]  ? entry_SYSENTER_compat+0x70/0x7f
[   45.375103]  ? trace_hardirqs_off_caller+0x310/0x310
[   45.380208]  __ia32_sys_mmap_pgoff+0xdd/0x1a0
[   45.384699]  do_fast_syscall_32+0x34d/0xfb2
[   45.389029]  ? do_int80_syscall_32+0x890/0x890
[   45.393600]  ? entry_SYSENTER_compat+0x68/0x7f
[   45.398172]  ? trace_hardirqs_off_caller+0xbb/0x310
[   45.403180]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   45.408019]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   45.412916]  ? trace_hardirqs_on_caller+0x310/0x310
[   45.417951]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   45.422963]  ? prepare_exit_to_usermode+0x291/0x3b0
[   45.427969]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   45.432807]  entry_SYSENTER_compat+0x70/0x7f
[   45.437200] RIP: 0023:0xf7f88a29
[   45.440552] 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
[   45.459558] RSP: 002b:00000000fffe6c7c EFLAGS: 00000282 ORIG_RAX: 00000000000000c0
[   45.467264] RAX: ffffffffffffffda RBX: 0000000020ffd000 RCX: 0000000000003000
[   45.474600] RDX: 0000000000000003 RSI: 0000000000000011 RDI: 0000000000000003
[   45.481877] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[   45.489133] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   45.496390] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   45.503654] 
[   45.505267] Allocated by task 5680:
[   45.508943]  save_stack+0x43/0xd0
[   45.512399]  kasan_kmalloc+0xc7/0xe0
[   45.516115]  __kmalloc+0x15b/0x760
[   45.519651]  __vb2_queue_alloc+0xf7/0xf90
[   45.523787]  vb2_core_reqbufs+0x971/0x1040
[   45.528011]  __vb2_init_fileio+0x344/0xc90
[   45.532238]  __vb2_perform_fileio+0xcfd/0x1210
[   45.536877]  vb2_write+0x38/0x50
[   45.540252]  vb2_fop_write+0x20a/0x400
[   45.544131]  v4l2_write+0x168/0x220
[   45.547744]  __vfs_write+0x119/0x9f0
[   45.551443]  vfs_write+0x1fc/0x560
[   45.554968]  ksys_write+0x101/0x260
[   45.558591]  __ia32_sys_write+0x71/0xb0
[   45.562549]  do_fast_syscall_32+0x34d/0xfb2
[   45.566964]  entry_SYSENTER_compat+0x70/0x7f
[   45.571369] 
[   45.573067] Freed by task 5680:
[   45.576345]  save_stack+0x43/0xd0
[   45.579788]  __kasan_slab_free+0x102/0x150
[   45.584019]  kasan_slab_free+0xe/0x10
[   45.587913]  kfree+0xcf/0x230
[   45.591019]  __vb2_queue_free+0x5e2/0xa30
[   45.595162]  vb2_core_reqbufs+0x2da/0x1040
[   45.599401]  __vb2_cleanup_fileio+0xf0/0x160
[   45.603809]  vb2_core_queue_release+0x1e/0x80
[   45.608296]  _vb2_fop_release+0x1d2/0x2b0
[   45.612434]  vb2_fop_release+0x77/0xc0
[   45.616310]  vivid_fop_release+0x18e/0x440
[   45.620528]  v4l2_release+0x224/0x3a0
[   45.624317]  __fput+0x385/0xa30
[   45.627655]  ____fput+0x15/0x20
[   45.630939]  task_work_run+0x1e8/0x2a0
[   45.634828]  exit_to_usermode_loop+0x318/0x380
[   45.639403]  do_fast_syscall_32+0xcd5/0xfb2
[   45.643714]  entry_SYSENTER_compat+0x70/0x7f
[   45.648106] 
[   45.649724] The buggy address belongs to the object at ffff8801d743fb00
[   45.649724]  which belongs to the cache kmalloc-1k of size 1024
[   45.662372] The buggy address is located 0 bytes inside of
[   45.662372]  1024-byte region [ffff8801d743fb00, ffff8801d743ff00)
[   45.674143] The buggy address belongs to the page:
[   45.679067] page:ffffea00075d0f80 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0 compound_mapcount: 0
[   45.689030] flags: 0x2fffc0000010200(slab|head)
[   45.693698] raw: 02fffc0000010200 ffffea00075d0f08 ffffea00075de388 ffff8801da800ac0
[   45.701569] raw: 0000000000000000 ffff8801d743e000 0000000100000007 0000000000000000
[   45.709531] page dumped because: kasan: bad access detected
[   45.715236] 
[   45.716849] Memory state around the buggy address:
[   45.721764]  ffff8801d743fa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.729110]  ffff8801d743fa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   45.736514] >ffff8801d743fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.743871]                    ^
[   45.747231]  ffff8801d743fb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.754573]  ffff8801d743fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[   45.762016] ==================================================================
[   45.769363] Disabling lock debugging due to kernel taint
[   45.776004] Kernel panic - not syncing: panic_on_warn set ...
[   45.781929] CPU: 1 PID: 5681 Comm: syz-executor400 Tainted: G    B             4.19.0+ #221
[   45.790400] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   45.799739] Call Trace:
[   45.802409]  dump_stack+0x244/0x39d
[   45.806045]  ? dump_stack_print_info.cold.1+0x20/0x20
[   45.811234]  panic+0x2ad/0x55c
[   45.814445]  ? add_taint.cold.5+0x16/0x16
[   45.818595]  ? preempt_schedule+0x4d/0x60
[   45.822735]  ? ___preempt_schedule+0x16/0x18
[   45.827131]  ? trace_hardirqs_on+0xb4/0x310
[   45.831531]  kasan_end_report+0x47/0x4f
[   45.835522]  kasan_report.cold.8+0x76/0x309
[   45.839843]  ? vb2_mmap+0x662/0x6f0
[   45.843457]  __asan_report_load8_noabort+0x14/0x20
[   45.848469]  vb2_mmap+0x662/0x6f0
[   45.851928]  ? vb2_poll+0x1d0/0x1d0
[   45.855552]  vb2_fop_mmap+0x4b/0x70
[   45.859178]  v4l2_mmap+0x153/0x200
[   45.862712]  mmap_region+0xe85/0x1cd0
[   45.866516]  ? __x64_sys_brk+0x8b0/0x8b0
[   45.870680]  ? zap_class+0x640/0x640
[   45.874409]  ? __kernel_text_address+0xd/0x40
[   45.878903]  ? mpx_unmapped_area_check+0xd8/0x108
[   45.883738]  ? arch_get_unmapped_area+0x750/0x750
[   45.888567]  ? lock_acquire+0x1ed/0x520
[   45.892533]  ? __sanitizer_cov_trace_cmp8+0x18/0x20
[   45.897541]  ? cap_mmap_addr+0x52/0x130
[   45.901506]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   45.907042]  ? security_mmap_addr+0x80/0xa0
[   45.911377]  ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[   45.917096]  ? get_unmapped_area+0x292/0x3b0
[   45.921587]  do_mmap+0xa22/0x1230
[   45.925048]  ? mmap_region+0x1cd0/0x1cd0
[   45.929102]  ? vm_mmap_pgoff+0x1b5/0x2c0
[   45.933172]  ? down_read_killable+0x150/0x150
[   45.937665]  ? security_mmap_file+0x174/0x1b0
[   45.942167]  vm_mmap_pgoff+0x213/0x2c0
[   45.946055]  ? vma_is_stack_for_current+0xd0/0xd0
[   45.950896]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   45.956445]  ? security_file_permission+0x1c2/0x220
[   45.961465]  ksys_mmap_pgoff+0x4da/0x660
[   45.965514]  ? do_fast_syscall_32+0x150/0xfb2
[   45.969995]  ? find_mergeable_anon_vma+0xd0/0xd0
[   45.974736]  ? trace_hardirqs_on+0xbd/0x310
[   45.979041]  ? __ia32_sys_read+0xb0/0xb0
[   45.983090]  ? entry_SYSENTER_compat+0x70/0x7f
[   45.987728]  ? trace_hardirqs_off_caller+0x310/0x310
[   45.992839]  __ia32_sys_mmap_pgoff+0xdd/0x1a0
[   45.997327]  do_fast_syscall_32+0x34d/0xfb2
[   46.001638]  ? do_int80_syscall_32+0x890/0x890
[   46.006267]  ? entry_SYSENTER_compat+0x68/0x7f
[   46.010855]  ? trace_hardirqs_off_caller+0xbb/0x310
[   46.015875]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   46.020719]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   46.025553]  ? trace_hardirqs_on_caller+0x310/0x310
[   46.030560]  ? prepare_exit_to_usermode+0x3b0/0x3b0
[   46.035576]  ? prepare_exit_to_usermode+0x291/0x3b0
[   46.040674]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   46.045531]  entry_SYSENTER_compat+0x70/0x7f
[   46.049955] RIP: 0023:0xf7f88a29
[   46.053421] 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
[   46.072319] RSP: 002b:00000000fffe6c7c EFLAGS: 00000282 ORIG_RAX: 00000000000000c0
[   46.080012] RAX: ffffffffffffffda RBX: 0000000020ffd000 RCX: 0000000000003000
[   46.087353] RDX: 0000000000000003 RSI: 0000000000000011 RDI: 0000000000000003
[   46.094665] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[   46.102010] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   46.109364] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   46.117725] Kernel Offset: disabled
[   46.121360] Rebooting in 86400 seconds..