[....] Starting enhanced syslogd: rsyslogd[ 16.761487] audit: type=1400 audit(1520527156.602:5): avc: denied { syslog } for pid=4071 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: [ 23.061629] audit: type=1400 audit(1520527162.902:6): avc: denied { map } for pid=4211 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 '10.128.0.16' (ECDSA) to the list of known hosts. [ 29.323573] audit: type=1400 audit(1520527169.164:7): avc: denied { map } for pid=4225 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 16:39:29 parsed 1 programs 2018/03/08 16:39:29 executed programs: 0 [ 29.554171] audit: type=1400 audit(1520527169.395:8): avc: denied { map } for pid=4225 comm="syz-execprog" path="/root/syzkaller-shm643112320" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:file_t:s0 tclass=file permissive=1 [ 29.563706] IPVS: ftp: loaded support on port[0] = 21 [ 29.610522] ================================================================== [ 29.617937] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 29.624053] Read of size 8 at addr ffff8801b32b6440 by task syz-executor0/4234 [ 29.631379] [ 29.632981] CPU: 0 PID: 4234 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #256 [ 29.640225] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.649547] Call Trace: [ 29.652109] dump_stack+0x194/0x24d [ 29.655709] ? arch_local_irq_restore+0x53/0x53 [ 29.660352] ? show_regs_print_info+0x18/0x18 [ 29.664816] ? save_stack+0xa3/0xd0 [ 29.668515] ? ucma_close+0x2d7/0x2f0 [ 29.672299] print_address_description+0x73/0x250 [ 29.677113] ? ucma_close+0x2d7/0x2f0 [ 29.680886] kasan_report+0x23c/0x360 [ 29.684662] __asan_report_load8_noabort+0x14/0x20 [ 29.689561] ucma_close+0x2d7/0x2f0 [ 29.693162] ? __might_sleep+0x95/0x190 [ 29.697108] ? ucma_free_ctx+0xd90/0xd90 [ 29.701141] __fput+0x327/0x7e0 [ 29.704398] ? fput+0x140/0x140 [ 29.707650] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.712124] ____fput+0x15/0x20 [ 29.715374] task_work_run+0x199/0x270 [ 29.719238] ? task_work_cancel+0x210/0x210 [ 29.723529] ? _raw_spin_unlock+0x22/0x30 [ 29.727649] ? switch_task_namespaces+0x87/0xc0 [ 29.732295] do_exit+0x9bb/0x1ad0 [ 29.735719] ? ucma_create_id+0x45b/0x620 [ 29.739845] ? mm_update_next_owner+0x930/0x930 [ 29.744487] ? ucma_create_id+0x17b/0x620 [ 29.748606] ? ucma_get_event+0xa90/0xa90 [ 29.752732] ? __might_sleep+0x95/0x190 [ 29.756682] ? kasan_check_write+0x14/0x20 [ 29.760888] ? _copy_from_user+0x99/0x110 [ 29.765009] ? ucma_write+0x11f/0x3d0 [ 29.768781] ? ucma_get_event+0xa90/0xa90 [ 29.772899] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.777375] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.781838] ? __vfs_write+0xf7/0x970 [ 29.785609] ? rcu_note_context_switch+0x710/0x710 [ 29.790523] ? kernel_read+0x120/0x120 [ 29.794382] ? __might_sleep+0x95/0x190 [ 29.798332] ? _cond_resched+0x14/0x30 [ 29.802191] ? __inode_security_revalidate+0xd9/0x130 [ 29.807357] ? avc_policy_seqno+0x9/0x20 [ 29.811394] ? security_file_permission+0x89/0x1e0 [ 29.816302] ? compat_SyS_futex+0x288/0x380 [ 29.820591] ? vfs_write+0x224/0x510 [ 29.824282] do_group_exit+0x149/0x400 [ 29.828142] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.833301] ? SyS_write+0x184/0x220 [ 29.836986] ? __do_page_fault+0x3d6/0xc90 [ 29.841193] ? SyS_exit+0x30/0x30 [ 29.844618] ? SyS_read+0x220/0x220 [ 29.848225] ? do_fast_syscall_32+0x156/0xf9f [ 29.852692] ? do_group_exit+0x400/0x400 [ 29.856725] SyS_exit_group+0x1d/0x20 [ 29.860497] do_fast_syscall_32+0x3ec/0xf9f [ 29.864794] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.869345] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.874076] ? syscall_return_slowpath+0x2ac/0x550 [ 29.878976] ? prepare_exit_to_usermode+0x350/0x350 [ 29.883966] ? sysret32_from_system_call+0x5/0x3c [ 29.888781] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.893599] entry_SYSENTER_compat+0x70/0x7f [ 29.897976] RIP: 0023:0xf7f7ac99 [ 29.901310] RSP: 002b:00000000ffeafb6c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.908986] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.916227] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.923468] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.930707] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.937947] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.945209] [ 29.946807] Allocated by task 4234: [ 29.950403] save_stack+0x43/0xd0 [ 29.953824] kasan_kmalloc+0xad/0xe0 [ 29.957511] kmem_cache_alloc_trace+0x136/0x740 [ 29.962149] ucma_alloc_ctx+0xce/0x610 [ 29.966006] ucma_create_id+0x205/0x620 [ 29.969950] ucma_write+0x2d6/0x3d0 [ 29.973547] __vfs_write+0xef/0x970 [ 29.977143] vfs_write+0x189/0x510 [ 29.980651] SyS_write+0xef/0x220 [ 29.984075] do_fast_syscall_32+0x3ec/0xf9f [ 29.988367] entry_SYSENTER_compat+0x70/0x7f [ 29.992742] [ 29.994343] Freed by task 4234: [ 29.997592] save_stack+0x43/0xd0 [ 30.001016] __kasan_slab_free+0x11a/0x170 [ 30.005221] kasan_slab_free+0xe/0x10 [ 30.009005] kfree+0xd9/0x260 [ 30.012077] ucma_create_id+0x45b/0x620 [ 30.016023] ucma_write+0x2d6/0x3d0 [ 30.019618] __vfs_write+0xef/0x970 [ 30.023214] vfs_write+0x189/0x510 [ 30.026736] SyS_write+0xef/0x220 [ 30.030159] do_fast_syscall_32+0x3ec/0xf9f [ 30.034458] entry_SYSENTER_compat+0x70/0x7f [ 30.038832] [ 30.040431] The buggy address belongs to the object at ffff8801b32b63c0 [ 30.040431] which belongs to the cache kmalloc-256 of size 256 [ 30.053054] The buggy address is located 128 bytes inside of [ 30.053054] 256-byte region [ffff8801b32b63c0, ffff8801b32b64c0) [ 30.064894] The buggy address belongs to the page: [ 30.069792] page:ffffea0006ccad80 count:1 mapcount:0 mapping:ffff8801b32b6000 index:0x0 [ 30.077901] flags: 0x2fffc0000000100(slab) [ 30.082107] raw: 02fffc0000000100 ffff8801b32b6000 0000000000000000 000000010000000c [ 30.089959] raw: ffffea00072aac60 ffffea0006cf2460 ffff8801dac007c0 0000000000000000 [ 30.097806] page dumped because: kasan: bad access detected [ 30.103484] [ 30.105085] Memory state around the buggy address: [ 30.109982] ffff8801b32b6300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc [ 30.117311] ffff8801b32b6380: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 30.124639] >ffff8801b32b6400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.131965] ^ [ 30.137381] ffff8801b32b6480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 30.144708] ffff8801b32b6500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.152050] ================================================================== [ 30.159376] Disabling lock debugging due to kernel taint [ 30.164844] Kernel panic - not syncing: panic_on_warn set ... [ 30.164844] [ 30.172181] CPU: 0 PID: 4234 Comm: syz-executor0 Tainted: G B 4.16.0-rc4+ #256 [ 30.180723] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.190046] Call Trace: [ 30.192607] dump_stack+0x194/0x24d [ 30.196213] ? arch_local_irq_restore+0x53/0x53 [ 30.200855] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.205581] ? vsnprintf+0x1ed/0x1900 [ 30.209354] ? ucma_close+0x240/0x2f0 [ 30.213125] panic+0x1e4/0x41c [ 30.216288] ? refcount_error_report+0x214/0x214 [ 30.221017] ? add_taint+0x1c/0x50 [ 30.224526] ? add_taint+0x1c/0x50 [ 30.228036] ? ucma_close+0x2d7/0x2f0 [ 30.231807] kasan_end_report+0x50/0x50 [ 30.235751] kasan_report+0x149/0x360 [ 30.239521] __asan_report_load8_noabort+0x14/0x20 [ 30.244419] ucma_close+0x2d7/0x2f0 [ 30.248015] ? __might_sleep+0x95/0x190 [ 30.251958] ? ucma_free_ctx+0xd90/0xd90 [ 30.255991] __fput+0x327/0x7e0 [ 30.259244] ? fput+0x140/0x140 [ 30.262493] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.266959] ____fput+0x15/0x20 [ 30.270208] task_work_run+0x199/0x270 [ 30.274067] ? task_work_cancel+0x210/0x210 [ 30.278362] ? _raw_spin_unlock+0x22/0x30 [ 30.282482] ? switch_task_namespaces+0x87/0xc0 [ 30.287122] do_exit+0x9bb/0x1ad0 [ 30.290543] ? ucma_create_id+0x45b/0x620 [ 30.294659] ? mm_update_next_owner+0x930/0x930 [ 30.299299] ? ucma_create_id+0x17b/0x620 [ 30.303416] ? ucma_get_event+0xa90/0xa90 [ 30.307537] ? __might_sleep+0x95/0x190 [ 30.311484] ? kasan_check_write+0x14/0x20 [ 30.315688] ? _copy_from_user+0x99/0x110 [ 30.319808] ? ucma_write+0x11f/0x3d0 [ 30.323577] ? ucma_get_event+0xa90/0xa90 [ 30.327695] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.332181] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.336646] ? __vfs_write+0xf7/0x970 [ 30.340420] ? rcu_note_context_switch+0x710/0x710 [ 30.345321] ? kernel_read+0x120/0x120 [ 30.349182] ? __might_sleep+0x95/0x190 [ 30.353128] ? _cond_resched+0x14/0x30 [ 30.356986] ? __inode_security_revalidate+0xd9/0x130 [ 30.362144] ? avc_policy_seqno+0x9/0x20 [ 30.366184] ? security_file_permission+0x89/0x1e0 [ 30.371089] ? compat_SyS_futex+0x288/0x380 [ 30.375380] ? vfs_write+0x224/0x510 [ 30.379064] do_group_exit+0x149/0x400 [ 30.382918] ? compat_SyS_get_robust_list+0x300/0x300 [ 30.388074] ? SyS_write+0x184/0x220 [ 30.391759] ? __do_page_fault+0x3d6/0xc90 [ 30.395960] ? SyS_exit+0x30/0x30 [ 30.399381] ? SyS_read+0x220/0x220 [ 30.402979] ? do_fast_syscall_32+0x156/0xf9f [ 30.407443] ? do_group_exit+0x400/0x400 [ 30.411472] SyS_exit_group+0x1d/0x20 [ 30.415243] do_fast_syscall_32+0x3ec/0xf9f [ 30.419539] ? do_int80_syscall_32+0x9c0/0x9c0 [ 30.424091] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.428819] ? syscall_return_slowpath+0x2ac/0x550 [ 30.433716] ? prepare_exit_to_usermode+0x350/0x350 [ 30.438701] ? sysret32_from_system_call+0x5/0x3c [ 30.443513] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.448329] entry_SYSENTER_compat+0x70/0x7f [ 30.452706] RIP: 0023:0xf7f7ac99 [ 30.456038] RSP: 002b:00000000ffeafb6c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 30.463714] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 30.470954] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.478193] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 30.485435] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.492672] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.500290] Dumping ftrace buffer: [ 30.503797] (ftrace buffer empty) [ 30.507476] Kernel Offset: disabled [ 30.511072] Rebooting in 86400 seconds..