[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 67.027333][ T25] audit: type=1800 audit(1575345616.634:25): pid=9036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 67.048240][ T25] audit: type=1800 audit(1575345616.634:26): pid=9036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 67.069450][ T25] audit: type=1800 audit(1575345616.644:27): pid=9036 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 '10.128.1.40' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 79.025787][ T9193] ================================================================== [ 79.034144][ T9193] BUG: KASAN: slab-out-of-bounds in pipe_write+0xe30/0x1000 [ 79.041412][ T9193] Write of size 8 at addr ffff88809081e1a8 by task syz-executor942/9193 [ 79.049709][ T9193] [ 79.052026][ T9193] CPU: 0 PID: 9193 Comm: syz-executor942 Not tainted 5.4.0-syzkaller #0 [ 79.060327][ T9193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 79.070365][ T9193] Call Trace: [ 79.073649][ T9193] dump_stack+0x197/0x210 [ 79.077982][ T9193] ? pipe_write+0xe30/0x1000 [ 79.082574][ T9193] print_address_description.constprop.0.cold+0xd4/0x30b [ 79.089633][ T9193] ? pipe_write+0xe30/0x1000 [ 79.094240][ T9193] ? pipe_write+0xe30/0x1000 [ 79.098813][ T9193] __kasan_report.cold+0x1b/0x41 [ 79.103735][ T9193] ? pipe_write+0xe30/0x1000 [ 79.108355][ T9193] kasan_report+0x12/0x20 [ 79.112681][ T9193] __asan_report_store8_noabort+0x17/0x20 [ 79.118404][ T9193] pipe_write+0xe30/0x1000 [ 79.122815][ T9193] new_sync_write+0x4d3/0x770 [ 79.127475][ T9193] ? new_sync_read+0x800/0x800 [ 79.132243][ T9193] ? __fget+0x37f/0x550 [ 79.136389][ T9193] ? apparmor_file_permission+0x25/0x30 [ 79.141918][ T9193] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 79.148157][ T9193] ? security_file_permission+0x8f/0x380 [ 79.153857][ T9193] __vfs_write+0xe1/0x110 [ 79.158189][ T9193] vfs_write+0x268/0x5d0 [ 79.162437][ T9193] ksys_write+0x220/0x290 [ 79.166755][ T9193] ? __ia32_sys_read+0xb0/0xb0 [ 79.171508][ T9193] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 79.176954][ T9193] ? do_syscall_64+0x26/0x790 [ 79.181618][ T9193] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 79.187673][ T9193] ? do_syscall_64+0x26/0x790 [ 79.192350][ T9193] __x64_sys_write+0x73/0xb0 [ 79.196937][ T9193] do_syscall_64+0xfa/0x790 [ 79.201444][ T9193] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 79.207331][ T9193] RIP: 0033:0x4466c9 [ 79.211221][ T9193] Code: e8 5c b3 02 00 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 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 79.230822][ T9193] RSP: 002b:00007f7c9043cdb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 79.239220][ T9193] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004466c9 [ 79.247199][ T9193] RDX: 00000000fffffef3 RSI: 00000000200001c0 RDI: 0000000000000004 [ 79.255157][ T9193] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 79.263124][ T9193] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 79.271088][ T9193] R13: 00007ffe694d560f R14: 00007f7c9043d9c0 R15: 20c49ba5e353f7cf [ 79.279061][ T9193] [ 79.281378][ T9193] Allocated by task 9195: [ 79.285772][ T9193] save_stack+0x23/0x90 [ 79.289932][ T9193] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 79.295561][ T9193] kasan_kmalloc+0x9/0x10 [ 79.299935][ T9193] __kmalloc+0x163/0x770 [ 79.304167][ T9193] pipe_fcntl+0x3f7/0x8e0 [ 79.308487][ T9193] do_fcntl+0x255/0x1030 [ 79.312734][ T9193] __x64_sys_fcntl+0x16d/0x1e0 [ 79.317503][ T9193] do_syscall_64+0xfa/0x790 [ 79.322015][ T9193] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 79.327892][ T9193] [ 79.330233][ T9193] Freed by task 0: [ 79.334039][ T9193] (stack is not available) [ 79.338440][ T9193] [ 79.340874][ T9193] The buggy address belongs to the object at ffff88809081e180 [ 79.340874][ T9193] which belongs to the cache kmalloc-64 of size 64 [ 79.354862][ T9193] The buggy address is located 40 bytes inside of [ 79.354862][ T9193] 64-byte region [ffff88809081e180, ffff88809081e1c0) [ 79.368053][ T9193] The buggy address belongs to the page: [ 79.374384][ T9193] page:ffffea0002420780 refcount:1 mapcount:0 mapping:ffff8880aa400380 index:0x0 [ 79.383588][ T9193] raw: 00fffe0000000200 ffffea0002224708 ffffea0002257448 ffff8880aa400380 [ 79.392196][ T9193] raw: 0000000000000000 ffff88809081e000 0000000100000020 0000000000000000 [ 79.400761][ T9193] page dumped because: kasan: bad access detected [ 79.407150][ T9193] [ 79.409493][ T9193] Memory state around the buggy address: [ 79.415118][ T9193] ffff88809081e080: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc [ 79.423218][ T9193] ffff88809081e100: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc [ 79.431313][ T9193] >ffff88809081e180: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc [ 79.439357][ T9193] ^ [ 79.444840][ T9193] ffff88809081e200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 79.452941][ T9193] ffff88809081e280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 79.460987][ T9193] ================================================================== [ 79.469061][ T9193] Disabling lock debugging due to kernel taint [ 79.475338][ T9193] Kernel panic - not syncing: panic_on_warn set ... [ 79.482057][ T9193] CPU: 0 PID: 9193 Comm: syz-executor942 Tainted: G B 5.4.0-syzkaller #0 [ 79.491822][ T9193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 79.501868][ T9193] Call Trace: [ 79.505214][ T9193] dump_stack+0x197/0x210 [ 79.509532][ T9193] panic+0x2e3/0x75c [ 79.513408][ T9193] ? add_taint.cold+0x16/0x16 [ 79.518075][ T9193] ? pipe_write+0xe30/0x1000 [ 79.522680][ T9193] ? preempt_schedule+0x4b/0x60 [ 79.527576][ T9193] ? ___preempt_schedule+0x16/0x18 [ 79.532758][ T9193] ? trace_hardirqs_on+0x5e/0x240 [ 79.537878][ T9193] ? pipe_write+0xe30/0x1000 [ 79.542464][ T9193] end_report+0x47/0x4f [ 79.546644][ T9193] ? pipe_write+0xe30/0x1000 [ 79.551297][ T9193] __kasan_report.cold+0xe/0x41 [ 79.556143][ T9193] ? pipe_write+0xe30/0x1000 [ 79.560746][ T9193] kasan_report+0x12/0x20 [ 79.565064][ T9193] __asan_report_store8_noabort+0x17/0x20 [ 79.570907][ T9193] pipe_write+0xe30/0x1000 [ 79.575316][ T9193] new_sync_write+0x4d3/0x770 [ 79.579980][ T9193] ? new_sync_read+0x800/0x800 [ 79.584735][ T9193] ? __fget+0x37f/0x550 [ 79.588878][ T9193] ? apparmor_file_permission+0x25/0x30 [ 79.594426][ T9193] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 79.600722][ T9193] ? security_file_permission+0x8f/0x380 [ 79.606355][ T9193] __vfs_write+0xe1/0x110 [ 79.610670][ T9193] vfs_write+0x268/0x5d0 [ 79.614902][ T9193] ksys_write+0x220/0x290 [ 79.619317][ T9193] ? __ia32_sys_read+0xb0/0xb0 [ 79.624069][ T9193] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 79.629703][ T9193] ? do_syscall_64+0x26/0x790 [ 79.634381][ T9193] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 79.640436][ T9193] ? do_syscall_64+0x26/0x790 [ 79.645120][ T9193] __x64_sys_write+0x73/0xb0 [ 79.649722][ T9193] do_syscall_64+0xfa/0x790 [ 79.654221][ T9193] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 79.660697][ T9193] RIP: 0033:0x4466c9 [ 79.664580][ T9193] Code: e8 5c b3 02 00 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 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 79.684181][ T9193] RSP: 002b:00007f7c9043cdb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 79.692594][ T9193] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004466c9 [ 79.700561][ T9193] RDX: 00000000fffffef3 RSI: 00000000200001c0 RDI: 0000000000000004 [ 79.708523][ T9193] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 79.716481][ T9193] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 79.724454][ T9193] R13: 00007ffe694d560f R14: 00007f7c9043d9c0 R15: 20c49ba5e353f7cf [ 79.733781][ T9193] Kernel Offset: disabled [ 79.738149][ T9193] Rebooting in 86400 seconds..