[....] Starting enhanced syslogd: rsyslogd[ 17.425256] audit: type=1400 audit(1520598345.547:5): avc: denied { syslog } for pid=4088 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: [ 23.202279] audit: type=1400 audit(1520598351.324:6): avc: denied { map } for pid=4228 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 '10.128.10.5' (ECDSA) to the list of known hosts. [ 29.516625] audit: type=1400 audit(1520598357.638:7): avc: denied { map } for pid=4242 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 2018/03/09 12:25:57 parsed 1 programs 2018/03/09 12:25:57 executed programs: 0 [ 29.791368] audit: type=1400 audit(1520598357.912:8): avc: denied { map } for pid=4242 comm="syz-execprog" path="/root/syzkaller-shm000375780" 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 [ 29.803548] IPVS: ftp: loaded support on port[0] = 21 [ 29.848913] ================================================================== [ 29.856333] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 29.862461] Read of size 8 at addr ffff8801b1649e40 by task syz-executor0/4250 [ 29.869793] [ 29.871402] CPU: 1 PID: 4250 Comm: syz-executor0 Not tainted 4.16.0-rc4+ #256 [ 29.878652] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.887988] Call Trace: [ 29.890558] dump_stack+0x194/0x24d [ 29.894168] ? arch_local_irq_restore+0x53/0x53 [ 29.898818] ? show_regs_print_info+0x18/0x18 [ 29.903289] ? save_stack+0xa3/0xd0 [ 29.906912] ? ucma_close+0x2d7/0x2f0 [ 29.910697] print_address_description+0x73/0x250 [ 29.915517] ? ucma_close+0x2d7/0x2f0 [ 29.919303] kasan_report+0x23c/0x360 [ 29.923087] __asan_report_load8_noabort+0x14/0x20 [ 29.927997] ucma_close+0x2d7/0x2f0 [ 29.931607] ? __might_sleep+0x95/0x190 [ 29.935564] ? ucma_free_ctx+0xd90/0xd90 [ 29.939603] __fput+0x327/0x7e0 [ 29.942865] ? fput+0x140/0x140 [ 29.946127] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.950608] ____fput+0x15/0x20 [ 29.953876] task_work_run+0x199/0x270 [ 29.957752] ? task_work_cancel+0x210/0x210 [ 29.962056] ? _raw_spin_unlock+0x22/0x30 [ 29.966194] ? switch_task_namespaces+0x87/0xc0 [ 29.970851] do_exit+0x9bb/0x1ad0 [ 29.974295] ? ucma_create_id+0x45b/0x620 [ 29.978448] ? mm_update_next_owner+0x930/0x930 [ 29.983108] ? ucma_create_id+0x17b/0x620 [ 29.987237] ? ucma_get_event+0xa90/0xa90 [ 29.991370] ? __might_sleep+0x95/0x190 [ 29.995328] ? kasan_check_write+0x14/0x20 [ 29.999544] ? _copy_from_user+0x99/0x110 [ 30.003693] ? ucma_write+0x11f/0x3d0 [ 30.007481] ? ucma_get_event+0xa90/0xa90 [ 30.011626] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.016123] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.020606] ? __vfs_write+0xf7/0x970 [ 30.024402] ? rcu_note_context_switch+0x710/0x710 [ 30.029315] ? kernel_read+0x120/0x120 [ 30.033225] ? __might_sleep+0x95/0x190 [ 30.037192] ? _cond_resched+0x14/0x30 [ 30.041062] ? __inode_security_revalidate+0xd9/0x130 [ 30.046231] ? avc_policy_seqno+0x9/0x20 [ 30.050277] ? security_file_permission+0x89/0x1e0 [ 30.055207] ? compat_SyS_futex+0x288/0x380 [ 30.059509] ? vfs_write+0x224/0x510 [ 30.063210] do_group_exit+0x149/0x400 [ 30.067086] ? compat_SyS_get_robust_list+0x300/0x300 [ 30.072262] ? SyS_write+0x184/0x220 [ 30.075953] ? __do_page_fault+0x3d6/0xc90 [ 30.080168] ? SyS_exit+0x30/0x30 [ 30.083599] ? SyS_read+0x220/0x220 [ 30.087207] ? do_fast_syscall_32+0x156/0xf9f [ 30.091683] ? do_group_exit+0x400/0x400 [ 30.095728] SyS_exit_group+0x1d/0x20 [ 30.099520] do_fast_syscall_32+0x3ec/0xf9f [ 30.103833] ? do_int80_syscall_32+0x9c0/0x9c0 [ 30.108393] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.113132] ? syscall_return_slowpath+0x2ac/0x550 [ 30.118043] ? prepare_exit_to_usermode+0x350/0x350 [ 30.123055] ? sysret32_from_system_call+0x5/0x3c [ 30.127892] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.132724] entry_SYSENTER_compat+0x70/0x7f [ 30.137113] RIP: 0023:0xf7f87c99 [ 30.140457] RSP: 002b:00000000ffe1aa7c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 30.148147] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 30.155395] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.162649] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 30.169899] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.177151] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.185409] [ 30.187020] Allocated by task 4250: [ 30.190640] save_stack+0x43/0xd0 [ 30.194075] kasan_kmalloc+0xad/0xe0 [ 30.197766] kmem_cache_alloc_trace+0x136/0x740 [ 30.202416] ucma_alloc_ctx+0xce/0x610 [ 30.206280] ucma_create_id+0x205/0x620 [ 30.210235] ucma_write+0x2d6/0x3d0 [ 30.213839] __vfs_write+0xef/0x970 [ 30.217449] vfs_write+0x189/0x510 [ 30.220973] SyS_write+0xef/0x220 [ 30.224404] do_fast_syscall_32+0x3ec/0xf9f [ 30.228708] entry_SYSENTER_compat+0x70/0x7f [ 30.233092] [ 30.234695] Freed by task 4250: [ 30.237954] save_stack+0x43/0xd0 [ 30.241388] __kasan_slab_free+0x11a/0x170 [ 30.245601] kasan_slab_free+0xe/0x10 [ 30.249377] kfree+0xd9/0x260 [ 30.252464] ucma_create_id+0x45b/0x620 [ 30.256417] ucma_write+0x2d6/0x3d0 [ 30.260030] __vfs_write+0xef/0x970 [ 30.263640] vfs_write+0x189/0x510 [ 30.267159] SyS_write+0xef/0x220 [ 30.270592] do_fast_syscall_32+0x3ec/0xf9f [ 30.274901] entry_SYSENTER_compat+0x70/0x7f [ 30.279284] [ 30.280892] The buggy address belongs to the object at ffff8801b1649dc0 [ 30.280892] which belongs to the cache kmalloc-256 of size 256 [ 30.293528] The buggy address is located 128 bytes inside of [ 30.293528] 256-byte region [ffff8801b1649dc0, ffff8801b1649ec0) [ 30.305390] The buggy address belongs to the page: [ 30.310299] page:ffffea0006c59240 count:1 mapcount:0 mapping:ffff8801b1649000 index:0x0 [ 30.318422] flags: 0x2fffc0000000100(slab) [ 30.322645] raw: 02fffc0000000100 ffff8801b1649000 0000000000000000 000000010000000c [ 30.330503] raw: ffffea0007271ea0 ffffea0006c585e0 ffff8801dac007c0 0000000000000000 [ 30.338358] page dumped because: kasan: bad access detected [ 30.344045] [ 30.345660] Memory state around the buggy address: [ 30.350576] ffff8801b1649d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.357914] ffff8801b1649d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 30.365255] >ffff8801b1649e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.372591] ^ [ 30.378024] ffff8801b1649e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 30.385361] ffff8801b1649f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 30.392698] ================================================================== [ 30.400040] Disabling lock debugging due to kernel taint [ 30.405515] Kernel panic - not syncing: panic_on_warn set ... [ 30.405515] [ 30.412873] CPU: 1 PID: 4250 Comm: syz-executor0 Tainted: G B 4.16.0-rc4+ #256 [ 30.421422] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.430750] Call Trace: [ 30.433318] dump_stack+0x194/0x24d [ 30.436925] ? arch_local_irq_restore+0x53/0x53 [ 30.441574] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.446320] ? vsnprintf+0x1ed/0x1900 [ 30.450109] ? ucma_close+0x240/0x2f0 [ 30.453891] panic+0x1e4/0x41c [ 30.457067] ? refcount_error_report+0x214/0x214 [ 30.461806] ? add_taint+0x1c/0x50 [ 30.465324] ? add_taint+0x1c/0x50 [ 30.468843] ? ucma_close+0x2d7/0x2f0 [ 30.472620] kasan_end_report+0x50/0x50 [ 30.476574] kasan_report+0x149/0x360 [ 30.480354] __asan_report_load8_noabort+0x14/0x20 [ 30.485262] ucma_close+0x2d7/0x2f0 [ 30.488866] ? __might_sleep+0x95/0x190 [ 30.492817] ? ucma_free_ctx+0xd90/0xd90 [ 30.496857] __fput+0x327/0x7e0 [ 30.500115] ? fput+0x140/0x140 [ 30.503374] ? _raw_spin_unlock_irq+0x27/0x70 [ 30.507846] ____fput+0x15/0x20 [ 30.511101] task_work_run+0x199/0x270 [ 30.514966] ? task_work_cancel+0x210/0x210 [ 30.519265] ? _raw_spin_unlock+0x22/0x30 [ 30.523396] ? switch_task_namespaces+0x87/0xc0 [ 30.528053] do_exit+0x9bb/0x1ad0 [ 30.531482] ? ucma_create_id+0x45b/0x620 [ 30.535607] ? mm_update_next_owner+0x930/0x930 [ 30.540256] ? ucma_create_id+0x17b/0x620 [ 30.544379] ? ucma_get_event+0xa90/0xa90 [ 30.548503] ? __might_sleep+0x95/0x190 [ 30.552459] ? kasan_check_write+0x14/0x20 [ 30.556668] ? _copy_from_user+0x99/0x110 [ 30.560795] ? ucma_write+0x11f/0x3d0 [ 30.564571] ? ucma_get_event+0xa90/0xa90 [ 30.568697] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.573180] ? ucma_resolve_route+0x1a0/0x1a0 [ 30.577663] ? __vfs_write+0xf7/0x970 [ 30.581450] ? rcu_note_context_switch+0x710/0x710 [ 30.586364] ? kernel_read+0x120/0x120 [ 30.590246] ? __might_sleep+0x95/0x190 [ 30.594216] ? _cond_resched+0x14/0x30 [ 30.598091] ? __inode_security_revalidate+0xd9/0x130 [ 30.603261] ? avc_policy_seqno+0x9/0x20 [ 30.607301] ? security_file_permission+0x89/0x1e0 [ 30.612211] ? compat_SyS_futex+0x288/0x380 [ 30.616505] ? vfs_write+0x224/0x510 [ 30.620195] do_group_exit+0x149/0x400 [ 30.624056] ? compat_SyS_get_robust_list+0x300/0x300 [ 30.629223] ? SyS_write+0x184/0x220 [ 30.632919] ? __do_page_fault+0x3d6/0xc90 [ 30.637131] ? SyS_exit+0x30/0x30 [ 30.640565] ? SyS_read+0x220/0x220 [ 30.644191] ? do_fast_syscall_32+0x156/0xf9f [ 30.648676] ? do_group_exit+0x400/0x400 [ 30.652716] SyS_exit_group+0x1d/0x20 [ 30.656505] do_fast_syscall_32+0x3ec/0xf9f [ 30.660832] ? do_int80_syscall_32+0x9c0/0x9c0 [ 30.665392] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.670142] ? syscall_return_slowpath+0x2ac/0x550 [ 30.675062] ? prepare_exit_to_usermode+0x350/0x350 [ 30.680060] ? sysret32_from_system_call+0x5/0x3c [ 30.684886] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.689711] entry_SYSENTER_compat+0x70/0x7f [ 30.694096] RIP: 0023:0xf7f87c99 [ 30.697445] RSP: 002b:00000000ffe1aa7c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 30.705143] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 30.712388] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.719632] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 30.726879] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.734123] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.741868] Dumping ftrace buffer: [ 30.745382] (ftrace buffer empty) [ 30.749067] Kernel Offset: disabled [ 30.752668] Rebooting in 86400 seconds..