[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 59.983285][ T23] audit: type=1800 audit(1575344188.710:25): pid=8796 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 60.003196][ T23] audit: type=1800 audit(1575344188.710:26): pid=8796 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 60.023964][ T23] audit: type=1800 audit(1575344188.710:27): pid=8796 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 '10.128.0.176' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 70.380997][ T8958] ================================================================== [ 70.389227][ T8958] BUG: KASAN: slab-out-of-bounds in pipe_write+0xe30/0x1000 [ 70.396489][ T8958] Write of size 8 at addr ffff88808da3b7a8 by task syz-executor837/8958 [ 70.404780][ T8958] [ 70.407088][ T8958] CPU: 1 PID: 8958 Comm: syz-executor837 Not tainted 5.4.0-syzkaller #0 [ 70.415383][ T8958] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.425455][ T8958] Call Trace: [ 70.428731][ T8958] dump_stack+0x197/0x210 [ 70.433038][ T8958] ? pipe_write+0xe30/0x1000 [ 70.437605][ T8958] print_address_description.constprop.0.cold+0xd4/0x30b [ 70.444612][ T8958] ? pipe_write+0xe30/0x1000 [ 70.449180][ T8958] ? pipe_write+0xe30/0x1000 [ 70.453749][ T8958] __kasan_report.cold+0x1b/0x41 [ 70.458666][ T8958] ? pipe_write+0xe30/0x1000 [ 70.463234][ T8958] kasan_report+0x12/0x20 [ 70.467543][ T8958] __asan_report_store8_noabort+0x17/0x20 [ 70.473239][ T8958] pipe_write+0xe30/0x1000 [ 70.477644][ T8958] new_sync_write+0x4d3/0x770 [ 70.482298][ T8958] ? new_sync_read+0x800/0x800 [ 70.487043][ T8958] ? __fget+0x37f/0x550 [ 70.491181][ T8958] ? apparmor_file_permission+0x25/0x30 [ 70.496751][ T8958] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 70.502978][ T8958] ? security_file_permission+0x8f/0x380 [ 70.508601][ T8958] __vfs_write+0xe1/0x110 [ 70.512964][ T8958] vfs_write+0x268/0x5d0 [ 70.517197][ T8958] ksys_write+0x220/0x290 [ 70.521512][ T8958] ? __ia32_sys_read+0xb0/0xb0 [ 70.526263][ T8958] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 70.531701][ T8958] ? do_syscall_64+0x26/0x790 [ 70.536356][ T8958] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.542410][ T8958] ? do_syscall_64+0x26/0x790 [ 70.547167][ T8958] __x64_sys_write+0x73/0xb0 [ 70.551734][ T8958] do_syscall_64+0xfa/0x790 [ 70.556230][ T8958] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.562115][ T8958] RIP: 0033:0x4466c9 [ 70.565996][ T8958] 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 [ 70.585581][ T8958] RSP: 002b:00007f46fc469db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 70.594008][ T8958] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004466c9 [ 70.601960][ T8958] RDX: 00000000fffffef3 RSI: 00000000200001c0 RDI: 0000000000000004 [ 70.609920][ T8958] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 70.617874][ T8958] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 70.625857][ T8958] R13: 00007ffc368f6faf R14: 00007f46fc46a9c0 R15: 20c49ba5e353f7cf [ 70.633816][ T8958] [ 70.636120][ T8958] Allocated by task 8960: [ 70.640458][ T8958] save_stack+0x23/0x90 [ 70.644591][ T8958] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 70.650228][ T8958] kasan_kmalloc+0x9/0x10 [ 70.654536][ T8958] __kmalloc+0x163/0x770 [ 70.658756][ T8958] pipe_fcntl+0x3f7/0x8e0 [ 70.663061][ T8958] do_fcntl+0x255/0x1030 [ 70.670839][ T8958] __x64_sys_fcntl+0x16d/0x1e0 [ 70.675581][ T8958] do_syscall_64+0xfa/0x790 [ 70.680061][ T8958] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.685923][ T8958] [ 70.688275][ T8958] Freed by task 8687: [ 70.692247][ T8958] save_stack+0x23/0x90 [ 70.696428][ T8958] __kasan_slab_free+0x102/0x150 [ 70.701340][ T8958] kasan_slab_free+0xe/0x10 [ 70.705819][ T8958] kfree+0x10a/0x2c0 [ 70.709688][ T8958] __free_fdtable+0x62/0x80 [ 70.714165][ T8958] put_files_struct+0x253/0x2f0 [ 70.719022][ T8958] exit_files+0x83/0xb0 [ 70.723154][ T8958] do_exit+0x8b5/0x2ef0 [ 70.727285][ T8958] do_group_exit+0x135/0x360 [ 70.731849][ T8958] __x64_sys_exit_group+0x44/0x50 [ 70.736861][ T8958] do_syscall_64+0xfa/0x790 [ 70.741348][ T8958] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.747258][ T8958] [ 70.749573][ T8958] The buggy address belongs to the object at ffff88808da3b780 [ 70.749573][ T8958] which belongs to the cache kmalloc-64 of size 64 [ 70.763443][ T8958] The buggy address is located 40 bytes inside of [ 70.763443][ T8958] 64-byte region [ffff88808da3b780, ffff88808da3b7c0) [ 70.776511][ T8958] The buggy address belongs to the page: [ 70.782121][ T8958] page:ffffea0002368ec0 refcount:1 mapcount:0 mapping:ffff8880aa400380 index:0x0 [ 70.791215][ T8958] raw: 00fffe0000000200 ffffea0002690ec8 ffffea000256c348 ffff8880aa400380 [ 70.799788][ T8958] raw: 0000000000000000 ffff88808da3b000 0000000100000020 0000000000000000 [ 70.808344][ T8958] page dumped because: kasan: bad access detected [ 70.814728][ T8958] [ 70.817067][ T8958] Memory state around the buggy address: [ 70.822786][ T8958] ffff88808da3b680: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 70.830838][ T8958] ffff88808da3b700: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 70.838912][ T8958] >ffff88808da3b780: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc [ 70.846947][ T8958] ^ [ 70.852298][ T8958] ffff88808da3b800: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 70.860367][ T8958] ffff88808da3b880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc [ 70.868403][ T8958] ================================================================== [ 70.876436][ T8958] Disabling lock debugging due to kernel taint [ 70.884076][ T8958] Kernel panic - not syncing: panic_on_warn set ... [ 70.890680][ T8958] CPU: 1 PID: 8958 Comm: syz-executor837 Tainted: G B 5.4.0-syzkaller #0 [ 70.900378][ T8958] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.910407][ T8958] Call Trace: [ 70.913681][ T8958] dump_stack+0x197/0x210 [ 70.917988][ T8958] panic+0x2e3/0x75c [ 70.921861][ T8958] ? add_taint.cold+0x16/0x16 [ 70.926531][ T8958] ? pipe_write+0xe30/0x1000 [ 70.931098][ T8958] ? preempt_schedule+0x4b/0x60 [ 70.935927][ T8958] ? ___preempt_schedule+0x16/0x18 [ 70.941018][ T8958] ? trace_hardirqs_on+0x5e/0x240 [ 70.946020][ T8958] ? pipe_write+0xe30/0x1000 [ 70.950587][ T8958] end_report+0x47/0x4f [ 70.954718][ T8958] ? pipe_write+0xe30/0x1000 [ 70.959303][ T8958] __kasan_report.cold+0xe/0x41 [ 70.964135][ T8958] ? pipe_write+0xe30/0x1000 [ 70.968703][ T8958] kasan_report+0x12/0x20 [ 70.973016][ T8958] __asan_report_store8_noabort+0x17/0x20 [ 70.978717][ T8958] pipe_write+0xe30/0x1000 [ 70.983111][ T8958] new_sync_write+0x4d3/0x770 [ 70.987763][ T8958] ? new_sync_read+0x800/0x800 [ 70.992508][ T8958] ? __fget+0x37f/0x550 [ 70.996641][ T8958] ? apparmor_file_permission+0x25/0x30 [ 71.002185][ T8958] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 71.008401][ T8958] ? security_file_permission+0x8f/0x380 [ 71.014008][ T8958] __vfs_write+0xe1/0x110 [ 71.018343][ T8958] vfs_write+0x268/0x5d0 [ 71.022568][ T8958] ksys_write+0x220/0x290 [ 71.026888][ T8958] ? __ia32_sys_read+0xb0/0xb0 [ 71.031629][ T8958] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 71.037060][ T8958] ? do_syscall_64+0x26/0x790 [ 71.041711][ T8958] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.047754][ T8958] ? do_syscall_64+0x26/0x790 [ 71.052405][ T8958] __x64_sys_write+0x73/0xb0 [ 71.056975][ T8958] do_syscall_64+0xfa/0x790 [ 71.061469][ T8958] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 71.067337][ T8958] RIP: 0033:0x4466c9 [ 71.071214][ T8958] 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 [ 71.090793][ T8958] RSP: 002b:00007f46fc469db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 71.099188][ T8958] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004466c9 [ 71.107132][ T8958] RDX: 00000000fffffef3 RSI: 00000000200001c0 RDI: 0000000000000004 [ 71.115088][ T8958] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 71.123034][ T8958] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 71.130990][ T8958] R13: 00007ffc368f6faf R14: 00007f46fc46a9c0 R15: 20c49ba5e353f7cf [ 71.140097][ T8958] Kernel Offset: disabled [ 71.144425][ T8958] Rebooting in 86400 seconds..