[....] Starting enhanced syslogd: rsyslogd[ 15.449720] audit: type=1400 audit(1520493732.131:5): avc: denied { syslog } for pid=4006 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: [ 18.422074] audit: type=1400 audit(1520493735.103:6): avc: denied { map } for pid=4145 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 '10.128.0.55' (ECDSA) to the list of known hosts. [ 25.500541] audit: type=1400 audit(1520493742.182:7): avc: denied { map } for pid=4160 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 2018/03/08 07:22:22 parsed 1 programs 2018/03/08 07:22:22 executed programs: 0 [ 25.751683] audit: type=1400 audit(1520493742.433:8): avc: denied { map } for pid=4160 comm="syz-execprog" path="/root/syzkaller-shm425289424" 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 [ 25.767402] IPVS: ftp: loaded support on port[0] = 21 [ 25.809597] ================================================================== [ 25.817039] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 25.823157] Read of size 8 at addr ffff8801b6558700 by task syz-executor0/4169 [ 25.830487] [ 25.832094] CPU: 0 PID: 4169 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #255 [ 25.839339] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.848673] Call Trace: [ 25.851255] dump_stack+0x194/0x24d [ 25.854858] ? arch_local_irq_restore+0x53/0x53 [ 25.859499] ? show_regs_print_info+0x18/0x18 [ 25.863971] ? save_stack+0xa3/0xd0 [ 25.867589] ? ucma_close+0x2d7/0x2f0 [ 25.871365] print_address_description+0x73/0x250 [ 25.876182] ? ucma_close+0x2d7/0x2f0 [ 25.879958] kasan_report+0x23c/0x360 [ 25.883747] __asan_report_load8_noabort+0x14/0x20 [ 25.888653] ucma_close+0x2d7/0x2f0 [ 25.892253] ? __might_sleep+0x95/0x190 [ 25.896200] ? ucma_free_ctx+0xd90/0xd90 [ 25.900233] __fput+0x327/0x7e0 [ 25.903496] ? fput+0x140/0x140 [ 25.906759] ? _raw_spin_unlock_irq+0x27/0x70 [ 25.911240] ____fput+0x15/0x20 [ 25.914496] task_work_run+0x199/0x270 [ 25.918360] ? task_work_cancel+0x210/0x210 [ 25.922664] ? _raw_spin_unlock+0x22/0x30 [ 25.926788] ? switch_task_namespaces+0x87/0xc0 [ 25.931444] do_exit+0x9bb/0x1ad0 [ 25.934869] ? ucma_create_id+0x45b/0x620 [ 25.938993] ? mm_update_next_owner+0x930/0x930 [ 25.943635] ? ucma_create_id+0x17b/0x620 [ 25.947756] ? ucma_get_event+0xa90/0xa90 [ 25.951883] ? __might_sleep+0x95/0x190 [ 25.955837] ? kasan_check_write+0x14/0x20 [ 25.960051] ? _copy_from_user+0x99/0x110 [ 25.964186] ? ucma_write+0x11f/0x3d0 [ 25.967956] ? ucma_get_event+0xa90/0xa90 [ 25.972084] ? ucma_resolve_route+0x1a0/0x1a0 [ 25.976566] ? ucma_resolve_route+0x1a0/0x1a0 [ 25.981043] ? __vfs_write+0xf7/0x970 [ 25.984817] ? rcu_note_context_switch+0x710/0x710 [ 25.989720] ? kernel_read+0x120/0x120 [ 25.993580] ? __might_sleep+0x95/0x190 [ 25.997537] ? _cond_resched+0x14/0x30 [ 26.001396] ? __inode_security_revalidate+0xd9/0x130 [ 26.006559] ? avc_policy_seqno+0x9/0x20 [ 26.010599] ? security_file_permission+0x89/0x1e0 [ 26.015510] ? compat_SyS_futex+0x288/0x380 [ 26.019808] ? vfs_write+0x224/0x510 [ 26.023498] do_group_exit+0x149/0x400 [ 26.027363] ? compat_SyS_get_robust_list+0x300/0x300 [ 26.032529] ? SyS_write+0x184/0x220 [ 26.036216] ? __do_page_fault+0x3d6/0xc90 [ 26.040432] ? SyS_exit+0x30/0x30 [ 26.043865] ? SyS_read+0x220/0x220 [ 26.047466] ? do_fast_syscall_32+0x156/0xf9f [ 26.051939] ? do_group_exit+0x400/0x400 [ 26.055972] SyS_exit_group+0x1d/0x20 [ 26.059746] do_fast_syscall_32+0x3ec/0xf9f [ 26.064063] ? do_int80_syscall_32+0x9c0/0x9c0 [ 26.068627] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.073359] ? syscall_return_slowpath+0x2ac/0x550 [ 26.078261] ? prepare_exit_to_usermode+0x350/0x350 [ 26.083251] ? sysret32_from_system_call+0x5/0x3c [ 26.088083] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.092907] entry_SYSENTER_compat+0x70/0x7f [ 26.097285] RIP: 0023:0xf7f2ac99 [ 26.100620] RSP: 002b:00000000ffe4d8ec EFLAGS: 00000286 ORIG_RAX: 00000000000000fc [ 26.108297] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 26.115537] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 26.122779] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 26.130019] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 26.137259] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 26.144520] [ 26.146124] Allocated by task 4169: [ 26.149733] save_stack+0x43/0xd0 [ 26.153157] kasan_kmalloc+0xad/0xe0 [ 26.156841] kmem_cache_alloc_trace+0x136/0x740 [ 26.161484] ucma_alloc_ctx+0xce/0x610 [ 26.165352] ucma_create_id+0x205/0x620 [ 26.169298] ucma_write+0x2d6/0x3d0 [ 26.172895] __vfs_write+0xef/0x970 [ 26.176491] vfs_write+0x189/0x510 [ 26.180006] SyS_write+0xef/0x220 [ 26.183437] do_fast_syscall_32+0x3ec/0xf9f [ 26.187729] entry_SYSENTER_compat+0x70/0x7f [ 26.192107] [ 26.193704] Freed by task 4169: [ 26.196954] save_stack+0x43/0xd0 [ 26.200377] __kasan_slab_free+0x11a/0x170 [ 26.204583] kasan_slab_free+0xe/0x10 [ 26.208354] kfree+0xd9/0x260 [ 26.211437] ucma_create_id+0x45b/0x620 [ 26.215392] ucma_write+0x2d6/0x3d0 [ 26.218988] __vfs_write+0xef/0x970 [ 26.222586] vfs_write+0x189/0x510 [ 26.226096] SyS_write+0xef/0x220 [ 26.229522] do_fast_syscall_32+0x3ec/0xf9f [ 26.233816] entry_SYSENTER_compat+0x70/0x7f [ 26.238197] [ 26.239798] The buggy address belongs to the object at ffff8801b6558680 [ 26.239798] which belongs to the cache kmalloc-256 of size 256 [ 26.252423] The buggy address is located 128 bytes inside of [ 26.252423] 256-byte region [ffff8801b6558680, ffff8801b6558780) [ 26.264264] The buggy address belongs to the page: [ 26.269164] page:ffffea0006d95600 count:1 mapcount:0 mapping:ffff8801b6558040 index:0xffff8801b6558180 [ 26.278582] flags: 0x2fffc0000000100(slab) [ 26.282794] raw: 02fffc0000000100 ffff8801b6558040 ffff8801b6558180 000000010000000a [ 26.290663] raw: ffffea0006dfc720 ffffea0006f9f3a0 ffff8801dac007c0 0000000000000000 [ 26.298516] page dumped because: kasan: bad access detected [ 26.304195] [ 26.305795] Memory state around the buggy address: [ 26.310695] ffff8801b6558600: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc [ 26.318022] ffff8801b6558680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.325350] >ffff8801b6558700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 26.332675] ^ [ 26.336014] ffff8801b6558780: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 [ 26.343351] ffff8801b6558800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 26.350677] ================================================================== [ 26.358004] Disabling lock debugging due to kernel taint [ 26.363471] Kernel panic - not syncing: panic_on_warn set ... [ 26.363471] [ 26.370821] CPU: 0 PID: 4169 Comm: syz-executor0 Tainted: G B 4.16.0-rc4+ #255 [ 26.379364] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 26.388687] Call Trace: [ 26.391246] dump_stack+0x194/0x24d [ 26.394844] ? arch_local_irq_restore+0x53/0x53 [ 26.399486] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.404212] ? vsnprintf+0x1ed/0x1900 [ 26.407984] ? ucma_close+0x240/0x2f0 [ 26.411758] panic+0x1e4/0x41c [ 26.414922] ? refcount_error_report+0x214/0x214 [ 26.419647] ? add_taint+0x1c/0x50 [ 26.423161] ? add_taint+0x1c/0x50 [ 26.426673] ? ucma_close+0x2d7/0x2f0 [ 26.430441] kasan_end_report+0x50/0x50 [ 26.434383] kasan_report+0x149/0x360 [ 26.438154] __asan_report_load8_noabort+0x14/0x20 [ 26.443051] ucma_close+0x2d7/0x2f0 [ 26.446650] ? __might_sleep+0x95/0x190 [ 26.450606] ? ucma_free_ctx+0xd90/0xd90 [ 26.454638] __fput+0x327/0x7e0 [ 26.457891] ? fput+0x140/0x140 [ 26.461141] ? _raw_spin_unlock_irq+0x27/0x70 [ 26.465605] ____fput+0x15/0x20 [ 26.468854] task_work_run+0x199/0x270 [ 26.472713] ? task_work_cancel+0x210/0x210 [ 26.477005] ? _raw_spin_unlock+0x22/0x30 [ 26.481128] ? switch_task_namespaces+0x87/0xc0 [ 26.485768] do_exit+0x9bb/0x1ad0 [ 26.489190] ? ucma_create_id+0x45b/0x620 [ 26.493309] ? mm_update_next_owner+0x930/0x930 [ 26.497947] ? ucma_create_id+0x17b/0x620 [ 26.502063] ? ucma_get_event+0xa90/0xa90 [ 26.506183] ? __might_sleep+0x95/0x190 [ 26.510127] ? kasan_check_write+0x14/0x20 [ 26.514330] ? _copy_from_user+0x99/0x110 [ 26.518447] ? ucma_write+0x11f/0x3d0 [ 26.522214] ? ucma_get_event+0xa90/0xa90 [ 26.526330] ? ucma_resolve_route+0x1a0/0x1a0 [ 26.530797] ? ucma_resolve_route+0x1a0/0x1a0 [ 26.535260] ? __vfs_write+0xf7/0x970 [ 26.539035] ? rcu_note_context_switch+0x710/0x710 [ 26.543934] ? kernel_read+0x120/0x120 [ 26.547791] ? __might_sleep+0x95/0x190 [ 26.551735] ? _cond_resched+0x14/0x30 [ 26.555592] ? __inode_security_revalidate+0xd9/0x130 [ 26.560760] ? avc_policy_seqno+0x9/0x20 [ 26.564797] ? security_file_permission+0x89/0x1e0 [ 26.569700] ? compat_SyS_futex+0x288/0x380 [ 26.573988] ? vfs_write+0x224/0x510 [ 26.577675] do_group_exit+0x149/0x400 [ 26.581534] ? compat_SyS_get_robust_list+0x300/0x300 [ 26.586691] ? SyS_write+0x184/0x220 [ 26.590378] ? __do_page_fault+0x3d6/0xc90 [ 26.594587] ? SyS_exit+0x30/0x30 [ 26.598023] ? SyS_read+0x220/0x220 [ 26.601626] ? do_fast_syscall_32+0x156/0xf9f [ 26.606102] ? do_group_exit+0x400/0x400 [ 26.610135] SyS_exit_group+0x1d/0x20 [ 26.613908] do_fast_syscall_32+0x3ec/0xf9f [ 26.618204] ? do_int80_syscall_32+0x9c0/0x9c0 [ 26.622754] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 26.627483] ? syscall_return_slowpath+0x2ac/0x550 [ 26.632382] ? prepare_exit_to_usermode+0x350/0x350 [ 26.637370] ? sysret32_from_system_call+0x5/0x3c [ 26.642182] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 26.646999] entry_SYSENTER_compat+0x70/0x7f [ 26.651380] RIP: 0023:0xf7f2ac99 [ 26.654713] RSP: 002b:00000000ffe4d8ec EFLAGS: 00000286 ORIG_RAX: 00000000000000fc [ 26.662389] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 26.669627] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 26.676864] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 26.684105] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 26.691342] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 26.699013] Dumping ftrace buffer: [ 26.702529] (ftrace buffer empty) [ 26.706207] Kernel Offset: disabled [ 26.709805] Rebooting in 86400 seconds..