[....] Starting enhanced syslogd: rsyslogd[ 16.005399] audit: type=1400 audit(1520799645.126:5): avc: denied { syslog } for pid=4013 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.305129] audit: type=1400 audit(1520799648.425:6): avc: denied { map } for pid=4154 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 '10.128.0.4' (ECDSA) to the list of known hosts. [ 29.451050] audit: type=1400 audit(1520799658.571:7): avc: denied { map } for pid=4169 comm="syz-execprog" path="/root/syz-execprog" dev="sda1" ino=16479 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 2018/03/11 20:20:58 parsed 1 programs 2018/03/11 20:20:58 executed programs: 0 [ 29.705680] audit: type=1400 audit(1520799658.826:8): avc: denied { map } for pid=4169 comm="syz-execprog" path="/root/syzkaller-shm056926714" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1 [ 29.719790] IPVS: ftp: loaded support on port[0] = 21 [ 29.764850] ================================================================== [ 29.772281] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 29.778415] Read of size 8 at addr ffff8801b5e6cdc0 by task syz-executor0/4177 [ 29.785751] [ 29.787353] CPU: 0 PID: 4177 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #259 [ 29.794594] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.803919] Call Trace: [ 29.806484] dump_stack+0x194/0x24d [ 29.810089] ? arch_local_irq_restore+0x53/0x53 [ 29.814734] ? show_regs_print_info+0x18/0x18 [ 29.819202] ? save_stack+0xa3/0xd0 [ 29.822810] ? ucma_close+0x2d7/0x2f0 [ 29.826595] print_address_description+0x73/0x250 [ 29.831419] ? ucma_close+0x2d7/0x2f0 [ 29.835191] kasan_report+0x23c/0x360 [ 29.838966] __asan_report_load8_noabort+0x14/0x20 [ 29.843868] ucma_close+0x2d7/0x2f0 [ 29.847472] ? __might_sleep+0x95/0x190 [ 29.851421] ? ucma_free_ctx+0xd90/0xd90 [ 29.855456] __fput+0x327/0x7e0 [ 29.858716] ? fput+0x140/0x140 [ 29.861976] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.866451] ____fput+0x15/0x20 [ 29.869705] task_work_run+0x199/0x270 [ 29.873580] ? task_work_cancel+0x210/0x210 [ 29.877877] ? _raw_spin_unlock+0x22/0x30 [ 29.882000] ? switch_task_namespaces+0x87/0xc0 [ 29.886646] do_exit+0x9bb/0x1ad0 [ 29.890071] ? ucma_create_id+0x45b/0x620 [ 29.894200] ? mm_update_next_owner+0x930/0x930 [ 29.898843] ? ucma_create_id+0x17b/0x620 [ 29.902973] ? ucma_get_event+0xa90/0xa90 [ 29.907100] ? __might_sleep+0x95/0x190 [ 29.911056] ? kasan_check_write+0x14/0x20 [ 29.915266] ? _copy_from_user+0x99/0x110 [ 29.919403] ? ucma_write+0x11f/0x3d0 [ 29.923176] ? ucma_get_event+0xa90/0xa90 [ 29.927300] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.931791] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.936267] ? __vfs_write+0xf7/0x970 [ 29.940055] ? rcu_note_context_switch+0x710/0x710 [ 29.944965] ? kernel_read+0x120/0x120 [ 29.948827] ? __might_sleep+0x95/0x190 [ 29.952777] ? _cond_resched+0x14/0x30 [ 29.956640] ? __inode_security_revalidate+0xd9/0x130 [ 29.961809] ? avc_policy_seqno+0x9/0x20 [ 29.965858] ? security_file_permission+0x89/0x1e0 [ 29.970774] ? compat_SyS_futex+0x288/0x380 [ 29.975069] ? vfs_write+0x224/0x510 [ 29.978768] do_group_exit+0x149/0x400 [ 29.982632] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.987797] ? SyS_write+0x184/0x220 [ 29.991486] ? __do_page_fault+0x3d6/0xc90 [ 29.995693] ? SyS_exit+0x30/0x30 [ 29.999120] ? SyS_read+0x220/0x220 [ 30.002724] ? do_fast_syscall_32+0x156/0xf9f [ 30.007197] ? do_group_exit+0x400/0x400 [ 30.011235] SyS_exit_group+0x1d/0x20 [ 30.015019] do_fast_syscall_32+0x3ec/0xf9f [ 30.019323] ? do_int80_syscall_32+0x9c0/0x9c0 [ 30.023880] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.028616] ? syscall_return_slowpath+0x2ac/0x550 [ 30.033536] ? prepare_exit_to_usermode+0x350/0x350 [ 30.038528] ? sysret32_from_system_call+0x5/0x3c [ 30.043349] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.048171] entry_SYSENTER_compat+0x70/0x7f [ 30.052562] RIP: 0023:0xf7fcec99 [ 30.055900] RSP: 002b:00000000ff941ecc EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 30.063589] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 30.070831] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.078072] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 30.085314] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.092560] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.099832] [ 30.101435] Allocated by task 4177: [ 30.105046] save_stack+0x43/0xd0 [ 30.108484] kasan_kmalloc+0xad/0xe0 [ 30.112172] kmem_cache_alloc_trace+0x136/0x740 [ 30.116816] ucma_alloc_ctx+0xce/0x610 [ 30.120678] ucma_create_id+0x205/0x620 [ 30.124632] ucma_write+0x2d6/0x3d0 [ 30.128232] __vfs_write+0xef/0x970 [ 30.131830] vfs_write+0x189/0x510 [ 30.135345] SyS_write+0xef/0x220 [ 30.138779] do_fast_syscall_32+0x3ec/0xf9f [ 30.143085] entry_SYSENTER_compat+0x70/0x7f [ 30.147475] [ 30.149084] Freed by task 4177: [ 30.152338] save_stack+0x43/0xd0 [ 30.155763] __kasan_slab_free+0x11a/0x170 [ 30.159969] kasan_slab_free+0xe/0x10 [ 30.163742] kfree+0xd9/0x260 [ 30.166828] ucma_create_id+0x45b/0x620 [ 30.170772] ucma_write+0x2d6/0x3d0 [ 30.174370] __vfs_write+0xef/0x970 [ 30.177969] vfs_write+0x189/0x510 [ 30.181485] SyS_write+0xef/0x220 [ 30.184913] do_fast_syscall_32+0x3ec/0xf9f [ 30.189210] entry_SYSENTER_compat+0x70/0x7f [ 30.193588] [ 30.195191] The buggy address belongs to the object at ffff8801b5e6cd40 [ 30.195191] which belongs to the cache kmalloc-256 of size 256 [ 30.207817] The buggy address is located 128 bytes inside of [ 30.207817] 256-byte region [ffff8801b5e6cd40, ffff8801b5e6ce40) [ 30.219660] The buggy address belongs to the page: [ 30.224572] page:ffffea0006d79b00 count:1 mapcount:0 mapping:ffff8801b5e6c0c0 index:0x0 [ 30.232688] flags: 0x2fffc0000000100(slab) [ 30.236893] raw: 02fffc0000000100 ffff8801b5e6c0c0 0000000000000000 000000010000000c [ 30.244748] raw: ffffea0006fa5320 ffffea0006dbee20 ffff8801dac007c0 0000000000000000 [ 30.252599] page dumped because: kasan: bad access detected [ 30.258277] [ 30.259895] Memory state around the buggy address: [ 30.264797] ffff8801b5e6cc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc [ 30.272137] ffff8801b5e6cd00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 30.279467] >ffff8801b5e6cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.286796] ^ [ 30.292216] ffff8801b5e6ce00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 30.299543] ffff8801b5e6ce80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.306872] ================================================================== [ 30.314202] Disabling lock debugging due to kernel taint [ 30.319665] Kernel panic - not syncing: panic_on_warn set ... [ 30.319665] [ 30.327028] CPU: 0 PID: 4177 Comm: syz-executor0 Tainted: G B 4.16.0-rc4+ #259 [ 30.335576] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.344903] Call Trace: [ 30.347470] dump_stack+0x194/0x24d [ 30.351068] ? arch_local_irq_restore+0x53/0x53 [ 30.355710] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.360435] ? vsnprintf+0x1ed/0x1900 [ 30.364206] ? ucma_close+0x280/0x2f0 [ 30.367977] panic+0x1e4/0x41c [ 30.371139] ? refcount_error_report+0x214/0x214 [ 30.375867] ? add_taint+0x1c/0x50 [ 30.379378] ? add_taint+0x1c/0x50 [ 30.382890] ? ucma_close+0x2d7/0x2f0 [ 30.386662] kasan_end_report+0x50/0x50 [ 30.390606] kasan_report+0x149/0x360 [ 30.394381] __asan_report_load8_noabort+0x14/0x20 [ 30.399280] ucma_close+0x2d7/0x2f0 [ 30.402878] ? __might_sleep+0x95/0x190 [ 30.406823] ? ucma_free_ctx+0xd90/0xd90 [ 30.410858] __fput+0x327/0x7e0 [ 30.414778] ? fput+0x140/0x140 [ 30.418033] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.422503] ____fput+0x15/0x20 [ 30.425755] task_work_run+0x199/0x270 [ 30.429616] ? task_work_cancel+0x210/0x210 [ 30.433910] ? _raw_spin_unlock+0x22/0x30 [ 30.438035] ? switch_task_namespaces+0x87/0xc0 [ 30.442679] do_exit+0x9bb/0x1ad0 [ 30.446105] ? ucma_create_id+0x45b/0x620 [ 30.450227] ? mm_update_next_owner+0x930/0x930 [ 30.454866] ? ucma_create_id+0x17b/0x620 [ 30.458982] ? ucma_get_event+0xa90/0xa90 [ 30.463108] ? __might_sleep+0x95/0x190 [ 30.467058] ? kasan_check_write+0x14/0x20 [ 30.471265] ? _copy_from_user+0x99/0x110 [ 30.475388] ? ucma_write+0x11f/0x3d0 [ 30.479166] ? ucma_get_event+0xa90/0xa90 [ 30.483287] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.487754] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.492217] ? __vfs_write+0xf7/0x970 [ 30.496001] ? rcu_note_context_switch+0x710/0x710 [ 30.500905] ? kernel_read+0x120/0x120 [ 30.504764] ? __might_sleep+0x95/0x190 [ 30.508712] ? _cond_resched+0x14/0x30 [ 30.512571] ? __inode_security_revalidate+0xd9/0x130 [ 30.517731] ? avc_policy_seqno+0x9/0x20 [ 30.521777] ? security_file_permission+0x89/0x1e0 [ 30.526683] ? compat_SyS_futex+0x288/0x380 [ 30.530972] ? vfs_write+0x224/0x510 [ 30.534674] do_group_exit+0x149/0x400 [ 30.538530] ? compat_SyS_get_robust_list+0x300/0x300 [ 30.543688] ? SyS_write+0x184/0x220 [ 30.547373] ? __do_page_fault+0x3d6/0xc90 [ 30.551582] ? SyS_exit+0x30/0x30 [ 30.555004] ? SyS_read+0x220/0x220 [ 30.558611] ? do_fast_syscall_32+0x156/0xf9f [ 30.563076] ? do_group_exit+0x400/0x400 [ 30.567105] SyS_exit_group+0x1d/0x20 [ 30.570878] do_fast_syscall_32+0x3ec/0xf9f [ 30.575170] ? do_int80_syscall_32+0x9c0/0x9c0 [ 30.579722] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.584450] ? syscall_return_slowpath+0x2ac/0x550 [ 30.589350] ? prepare_exit_to_usermode+0x350/0x350 [ 30.594339] ? sysret32_from_system_call+0x5/0x3c [ 30.599152] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.603967] entry_SYSENTER_compat+0x70/0x7f [ 30.608346] RIP: 0023:0xf7fcec99 [ 30.611681] RSP: 002b:00000000ff941ecc EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 30.619357] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 30.626595] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.633835] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 30.641075] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.648312] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.656064] Dumping ftrace buffer: [ 30.659580] (ftrace buffer empty) [ 30.663260] Kernel Offset: disabled [ 30.666857] Rebooting in 86400 seconds..