[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 32.168408] audit: type=1800 audit(1540914010.692:33): pid=5680 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 32.199398] audit: type=1800 audit(1540914010.692:34): pid=5680 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 [ 33.042583] audit: type=1400 audit(1540914011.562:35): avc: denied { map } for pid=5854 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.1' (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 syzkaller login: [ 39.817299] audit: type=1400 audit(1540914018.342:36): avc: denied { map } for pid=5868 comm="syz-executor261" path="/root/syz-executor261511861" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program executing program executing program executing program [ 39.870674] audit: type=1400 audit(1540914018.342:37): avc: denied { map } for pid=5875 comm="syz-executor261" path="/dev/video4" dev="devtmpfs" ino=16465 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:v4l_device_t:s0 tclass=chr_file permissive=1 [ 39.899719] ================================================================== [ 39.907301] BUG: KASAN: use-after-free in vb2_mmap+0x65f/0x6e0 [ 39.913268] Read of size 8 at addr ffff8801bb309780 by task syz-executor261/5884 executing program [ 39.920785] [ 39.922403] CPU: 0 PID: 5884 Comm: syz-executor261 Not tainted 4.19.0+ #90 [ 39.929402] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.938745] Call Trace: [ 39.941327] dump_stack+0x244/0x39d [ 39.944963] ? dump_stack_print_info.cold.1+0x20/0x20 [ 39.950152] ? printk+0xa7/0xcf [ 39.953420] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 39.958192] print_address_description.cold.7+0x9/0x1ff [ 39.963550] kasan_report.cold.8+0x242/0x309 [ 39.967966] ? vb2_mmap+0x65f/0x6e0 [ 39.971601] __asan_report_load8_noabort+0x14/0x20 [ 39.976524] vb2_mmap+0x65f/0x6e0 [ 39.979976] ? vb2_poll+0x1d0/0x1d0 [ 39.983612] vb2_fop_mmap+0x4b/0x70 [ 39.987259] v4l2_mmap+0x153/0x200 [ 39.990818] mmap_region+0xe85/0x1cd0 [ 39.994645] ? __x64_sys_brk+0x8b0/0x8b0 [ 39.998705] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.004258] ? inode_has_perm.isra.59+0x17a/0x210 [ 40.009129] ? mpx_unmapped_area_check+0xd8/0x108 [ 40.013962] ? selinux_file_open+0x5c0/0x5c0 [ 40.018363] ? arch_get_unmapped_area+0x750/0x750 [ 40.023195] ? lock_acquire+0x1ed/0x520 [ 40.027159] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.032696] ? selinux_mmap_addr+0x2d/0x110 [ 40.037036] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.042583] ? security_mmap_addr+0x80/0xa0 [ 40.046901] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.052427] ? get_unmapped_area+0x292/0x3b0 [ 40.056826] do_mmap+0xa22/0x1230 [ 40.060274] ? mmap_region+0x1cd0/0x1cd0 [ 40.064325] ? vm_mmap_pgoff+0x1b5/0x2c0 [ 40.068391] ? down_read_killable+0x150/0x150 [ 40.072916] ? security_mmap_file+0x174/0x1b0 [ 40.077433] vm_mmap_pgoff+0x213/0x2c0 [ 40.081328] ? vma_is_stack_for_current+0xd0/0xd0 [ 40.086170] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.091700] ? security_file_permission+0x1c2/0x220 [ 40.096712] ksys_mmap_pgoff+0x4da/0x660 [ 40.100766] ? do_syscall_64+0x9a/0x820 [ 40.104746] ? find_mergeable_anon_vma+0xd0/0xd0 [ 40.109491] ? trace_hardirqs_on+0xbd/0x310 [ 40.113801] ? __ia32_sys_read+0xb0/0xb0 [ 40.117860] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.123231] ? trace_hardirqs_off_caller+0x310/0x310 [ 40.128334] __x64_sys_mmap+0xe9/0x1b0 [ 40.132220] do_syscall_64+0x1b9/0x820 [ 40.136110] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.141483] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.146422] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.151262] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.156267] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.161275] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.166296] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.171142] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.176341] RIP: 0033:0x444ba9 [ 40.179526] 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 [ 40.198452] RSP: 002b:00007ffe11cf1e78 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 [ 40.206165] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444ba9 [ 40.213446] RDX: 0000000002000002 RSI: 0000000000001000 RDI: 0000000020fff000 [ 40.220706] RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 [ 40.227972] R10: 0000000000000013 R11: 0000000000000216 R12: 0000000000009b84 [ 40.235255] R13: 0000000000401ef0 R14: 0000000000000000 R15: 0000000000000000 [ 40.242572] [ 40.244207] Allocated by task 5890: [ 40.247830] save_stack+0x43/0xd0 [ 40.251277] kasan_kmalloc+0xc7/0xe0 [ 40.254991] __kmalloc+0x15b/0x760 [ 40.258548] __vb2_queue_alloc+0xf7/0xf20 [ 40.262711] vb2_core_reqbufs+0x971/0x1040 [ 40.266932] __vb2_init_fileio+0x344/0xc90 [ 40.271152] __vb2_perform_fileio+0xcfb/0x1210 [ 40.275718] vb2_write+0x38/0x50 [ 40.279075] vb2_fop_write+0x20a/0x400 [ 40.282949] v4l2_write+0x168/0x220 [ 40.286570] __vfs_write+0x119/0x9f0 [ 40.290296] vfs_write+0x1fc/0x560 [ 40.293849] ksys_write+0x101/0x260 [ 40.297470] __x64_sys_write+0x73/0xb0 [ 40.301344] do_syscall_64+0x1b9/0x820 [ 40.305224] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.310392] [ 40.312048] Freed by task 5890: [ 40.315318] save_stack+0x43/0xd0 [ 40.318760] __kasan_slab_free+0x102/0x150 [ 40.322980] kasan_slab_free+0xe/0x10 [ 40.326774] kfree+0xcf/0x230 [ 40.329879] __vb2_queue_free+0x5e2/0xa30 [ 40.334012] vb2_core_reqbufs+0x2da/0x1040 [ 40.338234] __vb2_cleanup_fileio+0xf0/0x160 [ 40.342646] vb2_core_queue_release+0x1e/0x80 [ 40.347158] _vb2_fop_release+0x1d2/0x2b0 [ 40.351299] vb2_fop_release+0x77/0xc0 [ 40.355182] vivid_fop_release+0x18e/0x440 [ 40.359429] v4l2_release+0xfb/0x1a0 [ 40.363157] __fput+0x385/0xa30 [ 40.366435] ____fput+0x15/0x20 [ 40.369730] task_work_run+0x1e8/0x2a0 [ 40.373632] exit_to_usermode_loop+0x318/0x380 [ 40.378208] do_syscall_64+0x6be/0x820 [ 40.378257] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.387366] [ 40.387377] The buggy address belongs to the object at ffff8801bb309780 [ 40.387377] which belongs to the cache kmalloc-512 of size 512 [ 40.387387] The buggy address is located 0 bytes inside of [ 40.387387] 512-byte region [ffff8801bb309780, ffff8801bb309980) [ 40.387392] The buggy address belongs to the page: [ 40.387402] page:ffffea0006ecc240 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0 [ 40.387417] flags: 0x2fffc0000000200(slab) [ 40.387445] raw: 02fffc0000000200 ffffea00074d0f48 ffff8801da801748 ffff8801da800940 [ 40.387459] raw: 0000000000000000 ffff8801bb309000 0000000100000006 0000000000000000 [ 40.387464] page dumped because: kasan: bad access detected [ 40.387468] [ 40.387483] Memory state around the buggy address: [ 40.387508] ffff8801bb309680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.387517] ffff8801bb309700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.387530] >ffff8801bb309780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.480814] ^ [ 40.484172] ffff8801bb309800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.491530] ffff8801bb309880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.498908] ================================================================== [ 40.506276] Disabling lock debugging due to kernel taint [ 40.511992] Kernel panic - not syncing: panic_on_warn set ... [ 40.511992] [ 40.519370] CPU: 0 PID: 5884 Comm: syz-executor261 Tainted: G B 4.19.0+ #90 [ 40.527759] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.537105] Call Trace: [ 40.539695] dump_stack+0x244/0x39d [ 40.543319] ? dump_stack_print_info.cold.1+0x20/0x20 [ 40.548506] panic+0x238/0x4e7 [ 40.551701] ? add_taint.cold.5+0x16/0x16 [ 40.555874] ? preempt_schedule+0x4d/0x60 [ 40.560019] ? ___preempt_schedule+0x16/0x18 [ 40.564432] ? trace_hardirqs_on+0xb4/0x310 [ 40.568756] kasan_end_report+0x47/0x4f [ 40.572723] kasan_report.cold.8+0x76/0x309 [ 40.577032] ? vb2_mmap+0x65f/0x6e0 [ 40.580649] __asan_report_load8_noabort+0x14/0x20 [ 40.585607] vb2_mmap+0x65f/0x6e0 [ 40.589085] ? vb2_poll+0x1d0/0x1d0 [ 40.592702] vb2_fop_mmap+0x4b/0x70 [ 40.596317] v4l2_mmap+0x153/0x200 [ 40.599854] mmap_region+0xe85/0x1cd0 [ 40.603654] ? __x64_sys_brk+0x8b0/0x8b0 [ 40.607709] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.613238] ? inode_has_perm.isra.59+0x17a/0x210 [ 40.618092] ? mpx_unmapped_area_check+0xd8/0x108 [ 40.622954] ? selinux_file_open+0x5c0/0x5c0 [ 40.627364] ? arch_get_unmapped_area+0x750/0x750 [ 40.632197] ? lock_acquire+0x1ed/0x520 [ 40.636164] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.641713] ? selinux_mmap_addr+0x2d/0x110 [ 40.646053] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.651592] ? security_mmap_addr+0x80/0xa0 [ 40.655900] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 40.661445] ? get_unmapped_area+0x292/0x3b0 [ 40.665845] do_mmap+0xa22/0x1230 [ 40.669286] ? mmap_region+0x1cd0/0x1cd0 [ 40.673337] ? vm_mmap_pgoff+0x1b5/0x2c0 [ 40.677396] ? down_read_killable+0x150/0x150 [ 40.681883] ? security_mmap_file+0x174/0x1b0 [ 40.686372] vm_mmap_pgoff+0x213/0x2c0 [ 40.690269] ? vma_is_stack_for_current+0xd0/0xd0 [ 40.695097] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 40.700640] ? security_file_permission+0x1c2/0x220 [ 40.705664] ksys_mmap_pgoff+0x4da/0x660 [ 40.709713] ? do_syscall_64+0x9a/0x820 [ 40.713707] ? find_mergeable_anon_vma+0xd0/0xd0 [ 40.718457] ? trace_hardirqs_on+0xbd/0x310 [ 40.722768] ? __ia32_sys_read+0xb0/0xb0 [ 40.726821] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.732179] ? trace_hardirqs_off_caller+0x310/0x310 [ 40.737286] __x64_sys_mmap+0xe9/0x1b0 [ 40.741176] do_syscall_64+0x1b9/0x820 [ 40.745069] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.750423] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.755339] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.760182] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.765195] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.770204] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.775211] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.780053] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.785242] RIP: 0033:0x444ba9 [ 40.788438] 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 [ 40.807332] RSP: 002b:00007ffe11cf1e78 EFLAGS: 00000216 ORIG_RAX: 0000000000000009 [ 40.815043] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444ba9 [ 40.822310] RDX: 0000000002000002 RSI: 0000000000001000 RDI: 0000000020fff000 [ 40.829584] RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 [ 40.836869] R10: 0000000000000013 R11: 0000000000000216 R12: 0000000000009b84 [ 40.844151] R13: 0000000000401ef0 R14: 0000000000000000 R15: 0000000000000000 [ 40.852310] Kernel Offset: disabled [ 40.855966] Rebooting in 86400 seconds..