[....] Starting enhanced syslogd: rsyslogd[ 16.824314] audit: type=1400 audit(1520744740.839:5): avc: denied { syslog } for pid=4060 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 mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] 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: [ 22.528308] audit: type=1400 audit(1520744746.543:6): avc: denied { map } for pid=4201 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. [ 28.812923] audit: type=1400 audit(1520744752.827:7): avc: denied { map } for pid=4215 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 05:05:53 parsed 1 programs 2018/03/11 05:05:53 executed programs: 0 [ 29.067721] audit: type=1400 audit(1520744753.082:8): avc: denied { map } for pid=4215 comm="syz-execprog" path="/root/syzkaller-shm156530385" 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 [ 29.081067] IPVS: ftp: loaded support on port[0] = 21 [ 29.124682] ================================================================== [ 29.132095] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 29.138212] Read of size 8 at addr ffff8801affa4c80 by task syz-executor0/4223 [ 29.145536] [ 29.147143] CPU: 0 PID: 4223 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #259 [ 29.154393] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.163716] Call Trace: [ 29.166278] dump_stack+0x194/0x24d [ 29.169889] ? arch_local_irq_restore+0x53/0x53 [ 29.174538] ? show_regs_print_info+0x18/0x18 [ 29.179960] ? save_stack+0xa3/0xd0 [ 29.183565] ? ucma_close+0x2d7/0x2f0 [ 29.187340] print_address_description+0x73/0x250 [ 29.192157] ? ucma_close+0x2d7/0x2f0 [ 29.195931] kasan_report+0x23c/0x360 [ 29.199709] __asan_report_load8_noabort+0x14/0x20 [ 29.204610] ucma_close+0x2d7/0x2f0 [ 29.208209] ? __might_sleep+0x95/0x190 [ 29.212166] ? ucma_free_ctx+0xd90/0xd90 [ 29.216204] __fput+0x327/0x7e0 [ 29.219462] ? fput+0x140/0x140 [ 29.222716] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.227188] ____fput+0x15/0x20 [ 29.230439] task_work_run+0x199/0x270 [ 29.234302] ? task_work_cancel+0x210/0x210 [ 29.238595] ? _raw_spin_unlock+0x22/0x30 [ 29.242716] ? switch_task_namespaces+0x87/0xc0 [ 29.247363] do_exit+0x9bb/0x1ad0 [ 29.250787] ? ucma_create_id+0x45b/0x620 [ 29.254913] ? mm_update_next_owner+0x930/0x930 [ 29.259556] ? ucma_create_id+0x17b/0x620 [ 29.263678] ? ucma_get_event+0xa90/0xa90 [ 29.267802] ? __might_sleep+0x95/0x190 [ 29.271759] ? kasan_check_write+0x14/0x20 [ 29.275969] ? _copy_from_user+0x99/0x110 [ 29.280092] ? ucma_write+0x11f/0x3d0 [ 29.283861] ? ucma_get_event+0xa90/0xa90 [ 29.287992] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.292473] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.296941] ? __vfs_write+0xf7/0x970 [ 29.300717] ? rcu_note_context_switch+0x710/0x710 [ 29.305622] ? kernel_read+0x120/0x120 [ 29.309482] ? __might_sleep+0x95/0x190 [ 29.313432] ? _cond_resched+0x14/0x30 [ 29.317294] ? __inode_security_revalidate+0xd9/0x130 [ 29.322455] ? avc_policy_seqno+0x9/0x20 [ 29.326494] ? security_file_permission+0x89/0x1e0 [ 29.331404] ? compat_SyS_futex+0x288/0x380 [ 29.335697] ? vfs_write+0x224/0x510 [ 29.339386] do_group_exit+0x149/0x400 [ 29.343248] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.348410] ? SyS_write+0x184/0x220 [ 29.352095] ? __do_page_fault+0x3d6/0xc90 [ 29.356302] ? SyS_exit+0x30/0x30 [ 29.359725] ? SyS_read+0x220/0x220 [ 29.363327] ? do_fast_syscall_32+0x156/0xf9f [ 29.367793] ? do_group_exit+0x400/0x400 [ 29.371825] SyS_exit_group+0x1d/0x20 [ 29.375598] do_fast_syscall_32+0x3ec/0xf9f [ 29.379898] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.384453] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.389187] ? syscall_return_slowpath+0x2ac/0x550 [ 29.394088] ? prepare_exit_to_usermode+0x350/0x350 [ 29.399081] ? sysret32_from_system_call+0x5/0x3c [ 29.403903] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.408722] entry_SYSENTER_compat+0x70/0x7f [ 29.413100] RIP: 0023:0xf7f92c99 [ 29.416437] RSP: 002b:00000000ffdce82c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.424116] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.431359] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.438598] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.445839] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.453079] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.460334] [ 29.461934] Allocated by task 4223: [ 29.465535] save_stack+0x43/0xd0 [ 29.468959] kasan_kmalloc+0xad/0xe0 [ 29.472644] kmem_cache_alloc_trace+0x136/0x740 [ 29.477282] ucma_alloc_ctx+0xce/0x610 [ 29.481142] ucma_create_id+0x205/0x620 [ 29.485085] ucma_write+0x2d6/0x3d0 [ 29.488685] __vfs_write+0xef/0x970 [ 29.492282] vfs_write+0x189/0x510 [ 29.495792] SyS_write+0xef/0x220 [ 29.499222] do_fast_syscall_32+0x3ec/0xf9f [ 29.503518] entry_SYSENTER_compat+0x70/0x7f [ 29.507902] [ 29.509500] Freed by task 4223: [ 29.512750] save_stack+0x43/0xd0 [ 29.516174] __kasan_slab_free+0x11a/0x170 [ 29.520380] kasan_slab_free+0xe/0x10 [ 29.524158] kfree+0xd9/0x260 [ 29.527240] ucma_create_id+0x45b/0x620 [ 29.531184] ucma_write+0x2d6/0x3d0 [ 29.534779] __vfs_write+0xef/0x970 [ 29.538375] vfs_write+0x189/0x510 [ 29.541884] SyS_write+0xef/0x220 [ 29.545310] do_fast_syscall_32+0x3ec/0xf9f [ 29.549603] entry_SYSENTER_compat+0x70/0x7f [ 29.553978] [ 29.555580] The buggy address belongs to the object at ffff8801affa4c00 [ 29.555580] which belongs to the cache kmalloc-256 of size 256 [ 29.568203] The buggy address is located 128 bytes inside of [ 29.568203] 256-byte region [ffff8801affa4c00, ffff8801affa4d00) [ 29.580045] The buggy address belongs to the page: [ 29.584945] page:ffffea0006bfe900 count:1 mapcount:0 mapping:ffff8801affa40c0 index:0xffff8801affa40c0 [ 29.594360] flags: 0x2fffc0000000100(slab) [ 29.598566] raw: 02fffc0000000100 ffff8801affa40c0 ffff8801affa40c0 0000000100000009 [ 29.606417] raw: ffffea0006d8e220 ffffea0006da14e0 ffff8801dac007c0 0000000000000000 [ 29.614268] page dumped because: kasan: bad access detected [ 29.619946] [ 29.621545] Memory state around the buggy address: [ 29.626444] ffff8801affa4b80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc [ 29.633773] ffff8801affa4c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.641101] >ffff8801affa4c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.648429] ^ [ 29.651767] ffff8801affa4d00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.659108] ffff8801affa4d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.666438] ================================================================== [ 29.673766] Disabling lock debugging due to kernel taint [ 29.679249] Kernel panic - not syncing: panic_on_warn set ... [ 29.679249] [ 29.686593] CPU: 0 PID: 4223 Comm: syz-executor0 Tainted: G B 4.16.0-rc4+ #259 [ 29.695139] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.704459] Call Trace: [ 29.707025] dump_stack+0x194/0x24d [ 29.710627] ? arch_local_irq_restore+0x53/0x53 [ 29.715269] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.719997] ? vsnprintf+0x1ed/0x1900 [ 29.723770] ? ucma_close+0x280/0x2f0 [ 29.727545] panic+0x1e4/0x41c [ 29.730708] ? refcount_error_report+0x214/0x214 [ 29.735434] ? add_taint+0x1c/0x50 [ 29.738945] ? add_taint+0x1c/0x50 [ 29.742457] ? ucma_close+0x2d7/0x2f0 [ 29.746225] kasan_end_report+0x50/0x50 [ 29.750167] kasan_report+0x149/0x360 [ 29.753940] __asan_report_load8_noabort+0x14/0x20 [ 29.758837] ucma_close+0x2d7/0x2f0 [ 29.762432] ? __might_sleep+0x95/0x190 [ 29.766376] ? ucma_free_ctx+0xd90/0xd90 [ 29.770408] __fput+0x327/0x7e0 [ 29.773659] ? fput+0x140/0x140 [ 29.776909] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.781376] ____fput+0x15/0x20 [ 29.784626] task_work_run+0x199/0x270 [ 29.788485] ? task_work_cancel+0x210/0x210 [ 29.792777] ? _raw_spin_unlock+0x22/0x30 [ 29.796896] ? switch_task_namespaces+0x87/0xc0 [ 29.801538] do_exit+0x9bb/0x1ad0 [ 29.804961] ? ucma_create_id+0x45b/0x620 [ 29.809082] ? mm_update_next_owner+0x930/0x930 [ 29.813721] ? ucma_create_id+0x17b/0x620 [ 29.817838] ? ucma_get_event+0xa90/0xa90 [ 29.821958] ? __might_sleep+0x95/0x190 [ 29.825903] ? kasan_check_write+0x14/0x20 [ 29.830126] ? _copy_from_user+0x99/0x110 [ 29.834245] ? ucma_write+0x11f/0x3d0 [ 29.838020] ? ucma_get_event+0xa90/0xa90 [ 29.842141] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.846610] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.851073] ? __vfs_write+0xf7/0x970 [ 29.854846] ? rcu_note_context_switch+0x710/0x710 [ 29.859746] ? kernel_read+0x120/0x120 [ 29.863603] ? __might_sleep+0x95/0x190 [ 29.867548] ? _cond_resched+0x14/0x30 [ 29.871406] ? __inode_security_revalidate+0xd9/0x130 [ 29.876562] ? avc_policy_seqno+0x9/0x20 [ 29.880597] ? security_file_permission+0x89/0x1e0 [ 29.885499] ? compat_SyS_futex+0x288/0x380 [ 29.889788] ? vfs_write+0x224/0x510 [ 29.893474] do_group_exit+0x149/0x400 [ 29.897328] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.902488] ? SyS_write+0x184/0x220 [ 29.906169] ? __do_page_fault+0x3d6/0xc90 [ 29.910370] ? SyS_exit+0x30/0x30 [ 29.913792] ? SyS_read+0x220/0x220 [ 29.917388] ? do_fast_syscall_32+0x156/0xf9f [ 29.921854] ? do_group_exit+0x400/0x400 [ 29.925885] SyS_exit_group+0x1d/0x20 [ 29.929656] do_fast_syscall_32+0x3ec/0xf9f [ 29.933950] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.938502] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.943231] ? syscall_return_slowpath+0x2ac/0x550 [ 29.948129] ? prepare_exit_to_usermode+0x350/0x350 [ 29.953115] ? sysret32_from_system_call+0x5/0x3c [ 29.957930] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.962744] entry_SYSENTER_compat+0x70/0x7f [ 29.967123] RIP: 0023:0xf7f92c99 [ 29.970453] RSP: 002b:00000000ffdce82c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.978129] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.985366] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.992605] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.999843] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.007082] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.014762] Dumping ftrace buffer: [ 30.018274] (ftrace buffer empty) [ 30.021953] Kernel Offset: disabled [ 30.025549] Rebooting in 86400 seconds..