[ 45.010882] audit: type=1800 audit(1555796503.243:30): pid=7695 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 51.426514] kauditd_printk_skb: 4 callbacks suppressed [ 51.426530] audit: type=1400 audit(1555796509.693:35): avc: denied { map } for pid=7869 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 Warning: Permanently added '10.128.1.33' (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 [ 696.908703] audit: type=1400 audit(1555797155.173:36): avc: denied { map } for pid=7881 comm="syz-executor672" path="/root/syz-executor672615674" dev="sda1" ino=1426 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 [ 696.973791] ================================================================== [ 696.983322] BUG: KASAN: use-after-free in __vb2_perform_fileio+0x105d/0x1140 [ 696.990542] Read of size 4 at addr ffff888092d6909c by task syz-executor672/7898 [ 696.998312] [ 696.999944] CPU: 0 PID: 7898 Comm: syz-executor672 Not tainted 4.19.36 #4 [ 697.007028] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 697.016458] Call Trace: [ 697.019422] dump_stack+0x172/0x1f0 [ 697.023272] ? __vb2_perform_fileio+0x105d/0x1140 [ 697.028337] print_address_description.cold+0x7c/0x20d [ 697.033623] ? __vb2_perform_fileio+0x105d/0x1140 [ 697.038464] kasan_report.cold+0x8c/0x2ba [ 697.042635] __asan_report_load4_noabort+0x14/0x20 [ 697.047852] __vb2_perform_fileio+0x105d/0x1140 [ 697.052538] ? vb2_thread_start+0x370/0x370 [ 697.056875] ? kasan_check_read+0x11/0x20 [ 697.061127] ? do_raw_spin_unlock+0x57/0x270 [ 697.065561] vb2_read+0x3b/0x50 [ 697.068877] vb2_fop_read+0x212/0x410 [ 697.072717] ? vb2_fop_write+0x410/0x410 [ 697.076900] v4l2_read+0x1ce/0x230 [ 697.080535] __vfs_read+0x116/0x800 [ 697.084214] ? v4l2_write+0x230/0x230 [ 697.088082] ? vfs_copy_file_range+0xba0/0xba0 [ 697.092746] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 697.098533] ? __inode_security_revalidate+0xda/0x120 [ 697.103902] ? avc_policy_seqno+0xd/0x70 [ 697.108066] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 697.113437] ? security_file_permission+0x1ce/0x230 [ 697.119078] ? security_file_permission+0x8f/0x230 [ 697.124081] ? rw_verify_area+0x118/0x360 [ 697.128261] vfs_read+0x194/0x3d0 [ 697.131810] ksys_pread64+0x183/0x1c0 [ 697.135606] ? __ia32_sys_write+0xb0/0xb0 [ 697.139824] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 697.144587] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 697.149428] ? do_syscall_64+0x26/0x610 [ 697.153529] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 697.158900] ? do_syscall_64+0x26/0x610 [ 697.163009] __x64_sys_pread64+0x97/0xf0 [ 697.167382] do_syscall_64+0x103/0x610 [ 697.171464] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 697.176986] RIP: 0033:0x444f09 [ 697.180181] 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 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 697.199128] RSP: 002b:00007fffc688cd98 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 [ 697.206868] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444f09 [ 697.214168] RDX: 000000000000008a RSI: 0000000020000140 RDI: 0000000000000003 [ 697.221497] RBP: 00000000000aa251 R08: 0000000000000004 R09: 00000000004002e0 [ 697.229276] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020a0 [ 697.236545] R13: 0000000000402130 R14: 0000000000000000 R15: 0000000000000000 [ 697.243828] [ 697.245514] Allocated by task 7898: [ 697.249232] save_stack+0x45/0xd0 [ 697.252683] kasan_kmalloc+0xce/0xf0 [ 697.256393] kmem_cache_alloc_trace+0x152/0x760 [ 697.261087] __vb2_init_fileio+0x1cb/0xbe0 [ 697.265576] __vb2_perform_fileio+0xbff/0x1140 [ 697.270177] vb2_read+0x3b/0x50 [ 697.273591] vb2_fop_read+0x212/0x410 [ 697.277421] v4l2_read+0x1ce/0x230 [ 697.280971] __vfs_read+0x116/0x800 [ 697.284596] vfs_read+0x194/0x3d0 [ 697.288104] ksys_pread64+0x183/0x1c0 [ 697.291966] __x64_sys_pread64+0x97/0xf0 [ 697.296025] do_syscall_64+0x103/0x610 [ 697.299913] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 697.305086] [ 697.306888] Freed by task 7895: [ 697.310214] save_stack+0x45/0xd0 [ 697.313877] __kasan_slab_free+0x102/0x150 [ 697.318299] kasan_slab_free+0xe/0x10 [ 697.322370] kfree+0xcf/0x230 [ 697.325651] __vb2_cleanup_fileio+0x100/0x170 [ 697.330267] vb2_core_queue_release+0x20/0x80 [ 697.334765] _vb2_fop_release+0x1cf/0x2a0 [ 697.338913] vb2_fop_release+0x75/0xc0 [ 697.342864] vivid_fop_release+0x18e/0x430 [ 697.347103] v4l2_release+0xfb/0x1a0 [ 697.350824] __fput+0x2df/0x8b0 [ 697.354126] ____fput+0x16/0x20 [ 697.357478] task_work_run+0x14a/0x1c0 [ 697.361414] do_exit+0x933/0x2fa0 [ 697.364876] do_group_exit+0x135/0x370 [ 697.368883] __x64_sys_exit_group+0x44/0x50 [ 697.373274] do_syscall_64+0x103/0x610 [ 697.377385] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 697.382564] [ 697.384221] The buggy address belongs to the object at ffff888092d68d80 [ 697.384221] which belongs to the cache kmalloc-1024 of size 1024 [ 697.397432] The buggy address is located 796 bytes inside of [ 697.397432] 1024-byte region [ffff888092d68d80, ffff888092d69180) [ 697.409504] The buggy address belongs to the page: [ 697.414447] page:ffffea00024b5a00 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0 [ 697.424435] flags: 0x1fffc0000008100(slab|head) [ 697.429142] raw: 01fffc0000008100 ffffea0002a8b988 ffffea0002a24e08 ffff88812c3f0ac0 [ 697.437072] raw: 0000000000000000 ffff888092d68000 0000000100000007 0000000000000000 [ 697.444963] page dumped because: kasan: bad access detected [ 697.450668] [ 697.452286] Memory state around the buggy address: [ 697.457207] ffff888092d68f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 697.464589] ffff888092d69000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 697.472554] >ffff888092d69080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 697.480382] ^ [ 697.484760] ffff888092d69100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 697.492357] ffff888092d69180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 697.499723] ================================================================== [ 697.507079] Disabling lock debugging due to kernel taint [ 697.513639] Kernel panic - not syncing: panic_on_warn set ... [ 697.513639] [ 697.521587] CPU: 1 PID: 7898 Comm: syz-executor672 Tainted: G B 4.19.36 #4 [ 697.529913] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 697.539260] Call Trace: [ 697.541849] dump_stack+0x172/0x1f0 [ 697.545478] ? __vb2_perform_fileio+0x105d/0x1140 [ 697.550476] panic+0x263/0x51d [ 697.553750] ? __warn_printk+0xf3/0xf3 [ 697.557756] ? __vb2_perform_fileio+0x105d/0x1140 [ 697.562625] ? preempt_schedule+0x4b/0x60 [ 697.567333] ? ___preempt_schedule+0x16/0x18 [ 697.579285] ? trace_hardirqs_on+0x5e/0x230 [ 697.583848] ? __vb2_perform_fileio+0x105d/0x1140 [ 697.588687] kasan_end_report+0x47/0x4f [ 697.592662] kasan_report.cold+0xa9/0x2ba [ 697.596884] __asan_report_load4_noabort+0x14/0x20 [ 697.601814] __vb2_perform_fileio+0x105d/0x1140 [ 697.606501] ? vb2_thread_start+0x370/0x370 [ 697.610937] ? kasan_check_read+0x11/0x20 [ 697.615086] ? do_raw_spin_unlock+0x57/0x270 [ 697.621727] vb2_read+0x3b/0x50 [ 697.625236] vb2_fop_read+0x212/0x410 [ 697.629140] ? vb2_fop_write+0x410/0x410 [ 697.633190] v4l2_read+0x1ce/0x230 [ 697.636735] __vfs_read+0x116/0x800 [ 697.640355] ? v4l2_write+0x230/0x230 [ 697.644158] ? vfs_copy_file_range+0xba0/0xba0 [ 697.648738] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 697.654274] ? __inode_security_revalidate+0xda/0x120 [ 697.659456] ? avc_policy_seqno+0xd/0x70 [ 697.663521] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 697.669457] ? security_file_permission+0x1ce/0x230 [ 697.674808] ? security_file_permission+0x8f/0x230 [ 697.680049] ? rw_verify_area+0x118/0x360 [ 697.684198] vfs_read+0x194/0x3d0 [ 697.687679] ksys_pread64+0x183/0x1c0 [ 697.691620] ? __ia32_sys_write+0xb0/0xb0 [ 697.695771] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 697.700525] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 697.705277] ? do_syscall_64+0x26/0x610 [ 697.709255] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 697.714629] ? do_syscall_64+0x26/0x610 [ 697.718817] __x64_sys_pread64+0x97/0xf0 [ 697.723144] do_syscall_64+0x103/0x610 [ 697.727073] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 697.732311] RIP: 0033:0x444f09 [ 697.735508] 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 0b cd fb ff c3 66 2e 0f 1f 84 00 00 00 00 [ 697.754539] RSP: 002b:00007fffc688cd98 EFLAGS: 00000246 ORIG_RAX: 0000000000000011 [ 697.762250] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444f09 [ 697.769743] RDX: 000000000000008a RSI: 0000000020000140 RDI: 0000000000000003 [ 697.777210] RBP: 00000000000aa251 R08: 0000000000000004 R09: 00000000004002e0 [ 697.784574] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020a0 [ 697.792031] R13: 0000000000402130 R14: 0000000000000000 R15: 0000000000000000 [ 697.800089] Kernel Offset: disabled [ 697.803758] Rebooting in 86400 seconds..