[....] Starting enhanced syslogd: rsyslogd[ 17.380428] audit: type=1400 audit(1520873413.105:5): avc: denied { syslog } for pid=4099 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 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: [ 22.451565] audit: type=1400 audit(1520873418.176:6): avc: denied { map } for pid=4239 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 '10.128.0.39' (ECDSA) to the list of known hosts. [ 28.767562] audit: type=1400 audit(1520873424.492:7): avc: denied { map } for pid=4253 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 2018/03/12 16:50:24 parsed 1 programs 2018/03/12 16:50:24 executed programs: 0 [ 29.000128] audit: type=1400 audit(1520873424.724:8): avc: denied { map } for pid=4253 comm="syz-execprog" path="/root/syzkaller-shm204297788" 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 [ 29.035599] IPVS: ftp: loaded support on port[0] = 21 [ 29.066439] ================================================================== [ 29.073851] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 29.079969] Read of size 8 at addr ffff8801b3fe8780 by task syz-executor0/4262 [ 29.087305] [ 29.088907] CPU: 1 PID: 4262 Comm: syz-executor0 Not tainted 4.16.0-rc5+ #261 [ 29.096151] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.105475] Call Trace: [ 29.108036] dump_stack+0x194/0x24d [ 29.111642] ? arch_local_irq_restore+0x53/0x53 [ 29.116293] ? show_regs_print_info+0x18/0x18 [ 29.120763] ? save_stack+0xa3/0xd0 [ 29.124366] ? ucma_close+0x2d7/0x2f0 [ 29.128141] print_address_description+0x73/0x250 [ 29.132957] ? ucma_close+0x2d7/0x2f0 [ 29.136731] kasan_report+0x23c/0x360 [ 29.140505] __asan_report_load8_noabort+0x14/0x20 [ 29.145417] ucma_close+0x2d7/0x2f0 [ 29.149023] ? __might_sleep+0x95/0x190 [ 29.152968] ? ucma_free_ctx+0xd90/0xd90 [ 29.157005] __fput+0x327/0x7e0 [ 29.160262] ? fput+0x140/0x140 [ 29.163518] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.168091] ____fput+0x15/0x20 [ 29.171344] task_work_run+0x199/0x270 [ 29.175210] ? task_work_cancel+0x210/0x210 [ 29.179508] ? _raw_spin_unlock+0x22/0x30 [ 29.183635] ? switch_task_namespaces+0x87/0xc0 [ 29.188294] do_exit+0x9bb/0x1ad0 [ 29.191721] ? ucma_create_id+0x45b/0x620 [ 29.195846] ? mm_update_next_owner+0x930/0x930 [ 29.200486] ? ucma_create_id+0x17b/0x620 [ 29.204610] ? ucma_get_event+0xa90/0xa90 [ 29.208743] ? __might_sleep+0x95/0x190 [ 29.212696] ? kasan_check_write+0x14/0x20 [ 29.216903] ? _copy_from_user+0x99/0x110 [ 29.221026] ? ucma_write+0x11f/0x3d0 [ 29.224794] ? ucma_get_event+0xa90/0xa90 [ 29.228923] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.233401] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.237870] ? __vfs_write+0xf7/0x970 [ 29.241650] ? rcu_note_context_switch+0x710/0x710 [ 29.246550] ? kernel_read+0x120/0x120 [ 29.250410] ? __might_sleep+0x95/0x190 [ 29.254368] ? _cond_resched+0x14/0x30 [ 29.258236] ? __inode_security_revalidate+0xd9/0x130 [ 29.263397] ? avc_policy_seqno+0x9/0x20 [ 29.267436] ? security_file_permission+0x89/0x1e0 [ 29.272349] ? compat_SyS_futex+0x288/0x380 [ 29.276641] ? vfs_write+0x224/0x510 [ 29.280333] do_group_exit+0x149/0x400 [ 29.284200] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.289362] ? SyS_write+0x184/0x220 [ 29.293048] ? __do_page_fault+0x3d6/0xc90 [ 29.297267] ? SyS_exit+0x30/0x30 [ 29.300701] ? SyS_read+0x220/0x220 [ 29.304316] ? do_fast_syscall_32+0x156/0xf9f [ 29.308794] ? do_group_exit+0x400/0x400 [ 29.312827] SyS_exit_group+0x1d/0x20 [ 29.316608] do_fast_syscall_32+0x3ec/0xf9f [ 29.320910] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.325464] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.330196] ? syscall_return_slowpath+0x2ac/0x550 [ 29.335101] ? prepare_exit_to_usermode+0x350/0x350 [ 29.340099] ? sysret32_from_system_call+0x5/0x3c [ 29.344937] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.349764] entry_SYSENTER_compat+0x70/0x7f [ 29.354142] RIP: 0023:0xf7fa1c99 [ 29.357474] RSP: 002b:00000000ffb54ccc EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.365154] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.372395] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.379635] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.386878] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.394120] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.401378] [ 29.402975] Allocated by task 4262: [ 29.406574] save_stack+0x43/0xd0 [ 29.409998] kasan_kmalloc+0xad/0xe0 [ 29.413682] kmem_cache_alloc_trace+0x136/0x740 [ 29.418318] ucma_alloc_ctx+0xce/0x610 [ 29.422175] ucma_create_id+0x205/0x620 [ 29.426120] ucma_write+0x2d6/0x3d0 [ 29.429727] __vfs_write+0xef/0x970 [ 29.433336] vfs_write+0x189/0x510 [ 29.436847] SyS_write+0xef/0x220 [ 29.440271] do_fast_syscall_32+0x3ec/0xf9f [ 29.444562] entry_SYSENTER_compat+0x70/0x7f [ 29.448934] [ 29.450529] Freed by task 4262: [ 29.453778] save_stack+0x43/0xd0 [ 29.457197] __kasan_slab_free+0x11a/0x170 [ 29.461399] kasan_slab_free+0xe/0x10 [ 29.465168] kfree+0xd9/0x260 [ 29.468243] ucma_create_id+0x45b/0x620 [ 29.472183] ucma_write+0x2d6/0x3d0 [ 29.475779] __vfs_write+0xef/0x970 [ 29.479373] vfs_write+0x189/0x510 [ 29.482881] SyS_write+0xef/0x220 [ 29.486305] do_fast_syscall_32+0x3ec/0xf9f [ 29.490596] entry_SYSENTER_compat+0x70/0x7f [ 29.494973] [ 29.496571] The buggy address belongs to the object at ffff8801b3fe8700 [ 29.496571] which belongs to the cache kmalloc-256 of size 256 [ 29.509196] The buggy address is located 128 bytes inside of [ 29.509196] 256-byte region [ffff8801b3fe8700, ffff8801b3fe8800) [ 29.521036] The buggy address belongs to the page: [ 29.525939] page:ffffea0006cffa00 count:1 mapcount:0 mapping:ffff8801b3fe80c0 index:0x0 [ 29.534055] flags: 0x2fffc0000000100(slab) [ 29.538261] raw: 02fffc0000000100 ffff8801b3fe80c0 0000000000000000 000000010000000c [ 29.546114] raw: ffffea0006d27360 ffffea0006cc80a0 ffff8801dac007c0 0000000000000000 [ 29.553960] page dumped because: kasan: bad access detected [ 29.559634] [ 29.561231] Memory state around the buggy address: [ 29.566129] ffff8801b3fe8680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 29.573458] ffff8801b3fe8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.580784] >ffff8801b3fe8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.588112] ^ [ 29.591444] ffff8801b3fe8800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.598773] ffff8801b3fe8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.606099] ================================================================== [ 29.613424] Disabling lock debugging due to kernel taint [ 29.618882] Kernel panic - not syncing: panic_on_warn set ... [ 29.618882] [ 29.626225] CPU: 1 PID: 4262 Comm: syz-executor0 Tainted: G B 4.16.0-rc5+ #261 [ 29.634777] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.644102] Call Trace: [ 29.646662] dump_stack+0x194/0x24d [ 29.650256] ? arch_local_irq_restore+0x53/0x53 [ 29.654894] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.659621] ? vsnprintf+0x1ed/0x1900 [ 29.663392] ? ucma_close+0x240/0x2f0 [ 29.667162] panic+0x1e4/0x41c [ 29.670321] ? refcount_error_report+0x214/0x214 [ 29.675054] ? add_taint+0x1c/0x50 [ 29.678561] ? add_taint+0x1c/0x50 [ 29.682073] ? ucma_close+0x2d7/0x2f0 [ 29.685842] kasan_end_report+0x50/0x50 [ 29.689784] kasan_report+0x149/0x360 [ 29.693556] __asan_report_load8_noabort+0x14/0x20 [ 29.698450] ucma_close+0x2d7/0x2f0 [ 29.702047] ? __might_sleep+0x95/0x190 [ 29.705991] ? ucma_free_ctx+0xd90/0xd90 [ 29.710021] __fput+0x327/0x7e0 [ 29.713274] ? fput+0x140/0x140 [ 29.716522] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.720994] ____fput+0x15/0x20 [ 29.724246] task_work_run+0x199/0x270 [ 29.728103] ? task_work_cancel+0x210/0x210 [ 29.732390] ? _raw_spin_unlock+0x22/0x30 [ 29.736508] ? switch_task_namespaces+0x87/0xc0 [ 29.741150] do_exit+0x9bb/0x1ad0 [ 29.744584] ? ucma_create_id+0x45b/0x620 [ 29.749231] ? mm_update_next_owner+0x930/0x930 [ 29.753876] ? ucma_create_id+0x17b/0x620 [ 29.757999] ? ucma_get_event+0xa90/0xa90 [ 29.762121] ? __might_sleep+0x95/0x190 [ 29.766065] ? kasan_check_write+0x14/0x20 [ 29.770267] ? _copy_from_user+0x99/0x110 [ 29.774382] ? ucma_write+0x11f/0x3d0 [ 29.778147] ? ucma_get_event+0xa90/0xa90 [ 29.782272] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.786744] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.791215] ? __vfs_write+0xf7/0x970 [ 29.795000] ? rcu_note_context_switch+0x710/0x710 [ 29.799902] ? kernel_read+0x120/0x120 [ 29.803758] ? __might_sleep+0x95/0x190 [ 29.807705] ? _cond_resched+0x14/0x30 [ 29.811561] ? __inode_security_revalidate+0xd9/0x130 [ 29.816721] ? avc_policy_seqno+0x9/0x20 [ 29.820754] ? security_file_permission+0x89/0x1e0 [ 29.825656] ? compat_SyS_futex+0x288/0x380 [ 29.829946] ? vfs_write+0x224/0x510 [ 29.833630] do_group_exit+0x149/0x400 [ 29.837487] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.842647] ? SyS_write+0x184/0x220 [ 29.846331] ? __do_page_fault+0x3d6/0xc90 [ 29.850538] ? SyS_exit+0x30/0x30 [ 29.853958] ? SyS_read+0x220/0x220 [ 29.857556] ? do_fast_syscall_32+0x156/0xf9f [ 29.862021] ? do_group_exit+0x400/0x400 [ 29.866052] SyS_exit_group+0x1d/0x20 [ 29.869824] do_fast_syscall_32+0x3ec/0xf9f [ 29.874118] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.878668] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.883396] ? syscall_return_slowpath+0x2ac/0x550 [ 29.888295] ? prepare_exit_to_usermode+0x350/0x350 [ 29.893283] ? sysret32_from_system_call+0x5/0x3c [ 29.898095] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.902908] entry_SYSENTER_compat+0x70/0x7f [ 29.907285] RIP: 0023:0xf7fa1c99 [ 29.910616] RSP: 002b:00000000ffb54ccc EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.918294] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.925535] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.932772] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.940009] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.947248] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.954865] Dumping ftrace buffer: [ 29.958375] (ftrace buffer empty) [ 29.962058] Kernel Offset: disabled [ 29.965653] Rebooting in 86400 seconds..