[....] Starting enhanced syslogd: rsyslogd[ 16.642265] audit: type=1400 audit(1521002242.651:5): avc: denied { syslog } for pid=4084 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: [ 22.196054] audit: type=1400 audit(1521002248.205:6): avc: denied { map } for pid=4223 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 '10.128.0.25' (ECDSA) to the list of known hosts. [ 28.456207] audit: type=1400 audit(1521002254.466:7): avc: denied { map } for pid=4237 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 2018/03/14 04:37:34 parsed 1 programs 2018/03/14 04:37:34 executed programs: 0 [ 28.705009] audit: type=1400 audit(1521002254.714:8): avc: denied { map } for pid=4237 comm="syz-execprog" path="/root/syzkaller-shm527834185" 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 [ 28.727757] IPVS: ftp: loaded support on port[0] = 21 [ 28.763446] ================================================================== [ 28.770880] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 28.776996] Read of size 8 at addr ffff8801b0177d80 by task syz-executor0/4246 [ 28.784327] [ 28.785928] CPU: 0 PID: 4246 Comm: syz-executor0 Not tainted 4.16.0-rc5+ #262 [ 28.793170] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.802494] Call Trace: [ 28.805058] dump_stack+0x194/0x24d [ 28.808660] ? arch_local_irq_restore+0x53/0x53 [ 28.813305] ? show_regs_print_info+0x18/0x18 [ 28.817775] ? save_stack+0xa3/0xd0 [ 28.821382] ? ucma_close+0x2d7/0x2f0 [ 28.825159] print_address_description+0x73/0x250 [ 28.829974] ? ucma_close+0x2d7/0x2f0 [ 28.833748] kasan_report+0x23c/0x360 [ 28.837524] __asan_report_load8_noabort+0x14/0x20 [ 28.842424] ucma_close+0x2d7/0x2f0 [ 28.846035] ? __might_sleep+0x95/0x190 [ 28.849991] ? ucma_free_ctx+0xd90/0xd90 [ 28.854033] __fput+0x327/0x7e0 [ 28.857299] ? fput+0x140/0x140 [ 28.860560] ? _raw_spin_unlock_irq+0x27/0x70 [ 28.865054] ____fput+0x15/0x20 [ 28.868313] task_work_run+0x199/0x270 [ 28.872178] ? task_work_cancel+0x210/0x210 [ 28.876475] ? _raw_spin_unlock+0x22/0x30 [ 28.880597] ? switch_task_namespaces+0x87/0xc0 [ 28.885244] do_exit+0x9bb/0x1ad0 [ 28.888669] ? ucma_create_id+0x45b/0x620 [ 28.892793] ? mm_update_next_owner+0x930/0x930 [ 28.897435] ? ucma_create_id+0x17b/0x620 [ 28.901557] ? ucma_get_event+0xa90/0xa90 [ 28.905686] ? __might_sleep+0x95/0x190 [ 28.909643] ? kasan_check_write+0x14/0x20 [ 28.913854] ? _copy_from_user+0x99/0x110 [ 28.917977] ? ucma_write+0x11f/0x3d0 [ 28.921748] ? ucma_get_event+0xa90/0xa90 [ 28.925868] ? ucma_resolve_route+0x1a0/0x1a0 [ 28.930344] ? ucma_resolve_route+0x1a0/0x1a0 [ 28.934811] ? __vfs_write+0xf7/0x970 [ 28.938584] ? rcu_note_context_switch+0x710/0x710 [ 28.943487] ? kernel_read+0x120/0x120 [ 28.947349] ? __might_sleep+0x95/0x190 [ 28.951303] ? _cond_resched+0x14/0x30 [ 28.955167] ? __inode_security_revalidate+0xd9/0x130 [ 28.960329] ? avc_policy_seqno+0x9/0x20 [ 28.964371] ? security_file_permission+0x89/0x1e0 [ 28.969283] ? compat_SyS_futex+0x288/0x380 [ 28.973579] ? vfs_write+0x224/0x510 [ 28.977270] do_group_exit+0x149/0x400 [ 28.981129] ? compat_SyS_get_robust_list+0x300/0x300 [ 28.986289] ? SyS_write+0x184/0x220 [ 28.989973] ? __do_page_fault+0x3d6/0xc90 [ 28.994180] ? SyS_exit+0x30/0x30 [ 28.997606] ? SyS_read+0x220/0x220 [ 29.001215] ? do_fast_syscall_32+0x156/0xf9f [ 29.005686] ? do_group_exit+0x400/0x400 [ 29.009721] SyS_exit_group+0x1d/0x20 [ 29.013495] do_fast_syscall_32+0x3ec/0xf9f [ 29.017795] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.022349] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.027084] ? syscall_return_slowpath+0x2ac/0x550 [ 29.031987] ? prepare_exit_to_usermode+0x350/0x350 [ 29.036980] ? sysret32_from_system_call+0x5/0x3c [ 29.041798] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.046622] entry_SYSENTER_compat+0x70/0x7f [ 29.051004] RIP: 0023:0xf7fcac99 [ 29.054345] RSP: 002b:00000000ff8331fc EFLAGS: 00000286 ORIG_RAX: 00000000000000fc [ 29.062029] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.069278] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.076521] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.083763] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.091007] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.098272] [ 29.099873] Allocated by task 4246: [ 29.103474] save_stack+0x43/0xd0 [ 29.106897] kasan_kmalloc+0xad/0xe0 [ 29.110583] kmem_cache_alloc_trace+0x136/0x740 [ 29.115228] ucma_alloc_ctx+0xce/0x610 [ 29.119085] ucma_create_id+0x205/0x620 [ 29.123034] ucma_write+0x2d6/0x3d0 [ 29.126642] __vfs_write+0xef/0x970 [ 29.130239] vfs_write+0x189/0x510 [ 29.133747] SyS_write+0xef/0x220 [ 29.137172] do_fast_syscall_32+0x3ec/0xf9f [ 29.141477] entry_SYSENTER_compat+0x70/0x7f [ 29.145850] [ 29.147450] Freed by task 4246: [ 29.150699] save_stack+0x43/0xd0 [ 29.154121] __kasan_slab_free+0x11a/0x170 [ 29.158325] kasan_slab_free+0xe/0x10 [ 29.162099] kfree+0xd9/0x260 [ 29.165175] ucma_create_id+0x45b/0x620 [ 29.169120] ucma_write+0x2d6/0x3d0 [ 29.172726] __vfs_write+0xef/0x970 [ 29.176322] vfs_write+0x189/0x510 [ 29.179831] SyS_write+0xef/0x220 [ 29.183256] do_fast_syscall_32+0x3ec/0xf9f [ 29.187550] entry_SYSENTER_compat+0x70/0x7f [ 29.191925] [ 29.193525] The buggy address belongs to the object at ffff8801b0177d00 [ 29.193525] which belongs to the cache kmalloc-256 of size 256 [ 29.206152] The buggy address is located 128 bytes inside of [ 29.206152] 256-byte region [ffff8801b0177d00, ffff8801b0177e00) [ 29.217993] The buggy address belongs to the page: [ 29.222896] page:ffffea0006c05dc0 count:1 mapcount:0 mapping:ffff8801b0177080 index:0x0 [ 29.231011] flags: 0x2fffc0000000100(slab) [ 29.235228] raw: 02fffc0000000100 ffff8801b0177080 0000000000000000 000000010000000c [ 29.243079] raw: ffffea0007378a20 ffffea0006c05ee0 ffff8801dac007c0 0000000000000000 [ 29.250926] page dumped because: kasan: bad access detected [ 29.256605] [ 29.258202] Memory state around the buggy address: [ 29.263106] ffff8801b0177c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 29.270443] ffff8801b0177d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.277771] >ffff8801b0177d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.285098] ^ [ 29.288433] ffff8801b0177e00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.295761] ffff8801b0177e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.303091] ================================================================== [ 29.310430] Disabling lock debugging due to kernel taint [ 29.315923] Kernel panic - not syncing: panic_on_warn set ... [ 29.315923] [ 29.323270] CPU: 0 PID: 4246 Comm: syz-executor0 Tainted: G B 4.16.0-rc5+ #262 [ 29.331823] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.341147] Call Trace: [ 29.343713] dump_stack+0x194/0x24d [ 29.347325] ? arch_local_irq_restore+0x53/0x53 [ 29.351966] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.356691] ? vsnprintf+0x1ed/0x1900 [ 29.360465] ? ucma_close+0x1f0/0x2f0 [ 29.364236] panic+0x1e4/0x41c [ 29.367401] ? refcount_error_report+0x214/0x214 [ 29.372130] ? add_taint+0x1c/0x50 [ 29.375642] ? add_taint+0x1c/0x50 [ 29.379153] ? ucma_close+0x2d7/0x2f0 [ 29.382933] kasan_end_report+0x50/0x50 [ 29.386881] kasan_report+0x149/0x360 [ 29.390652] __asan_report_load8_noabort+0x14/0x20 [ 29.395551] ucma_close+0x2d7/0x2f0 [ 29.399150] ? __might_sleep+0x95/0x190 [ 29.403095] ? ucma_free_ctx+0xd90/0xd90 [ 29.407130] __fput+0x327/0x7e0 [ 29.410384] ? fput+0x140/0x140 [ 29.413637] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.418109] ____fput+0x15/0x20 [ 29.421364] task_work_run+0x199/0x270 [ 29.425225] ? task_work_cancel+0x210/0x210 [ 29.429587] ? _raw_spin_unlock+0x22/0x30 [ 29.433716] ? switch_task_namespaces+0x87/0xc0 [ 29.438361] do_exit+0x9bb/0x1ad0 [ 29.441784] ? ucma_create_id+0x45b/0x620 [ 29.445906] ? mm_update_next_owner+0x930/0x930 [ 29.450545] ? ucma_create_id+0x17b/0x620 [ 29.454663] ? ucma_get_event+0xa90/0xa90 [ 29.458797] ? __might_sleep+0x95/0x190 [ 29.462745] ? kasan_check_write+0x14/0x20 [ 29.466970] ? _copy_from_user+0x99/0x110 [ 29.471095] ? ucma_write+0x11f/0x3d0 [ 29.474876] ? ucma_get_event+0xa90/0xa90 [ 29.478993] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.483464] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.487931] ? __vfs_write+0xf7/0x970 [ 29.491702] ? rcu_note_context_switch+0x710/0x710 [ 29.496612] ? kernel_read+0x120/0x120 [ 29.500473] ? __might_sleep+0x95/0x190 [ 29.504420] ? _cond_resched+0x14/0x30 [ 29.508279] ? __inode_security_revalidate+0xd9/0x130 [ 29.513440] ? avc_policy_seqno+0x9/0x20 [ 29.517475] ? security_file_permission+0x89/0x1e0 [ 29.522380] ? compat_SyS_futex+0x288/0x380 [ 29.526669] ? vfs_write+0x224/0x510 [ 29.530357] do_group_exit+0x149/0x400 [ 29.534214] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.539372] ? SyS_write+0x184/0x220 [ 29.543056] ? __do_page_fault+0x3d6/0xc90 [ 29.547266] ? SyS_exit+0x30/0x30 [ 29.550698] ? SyS_read+0x220/0x220 [ 29.554299] ? do_fast_syscall_32+0x156/0xf9f [ 29.558764] ? do_group_exit+0x400/0x400 [ 29.562795] SyS_exit_group+0x1d/0x20 [ 29.566573] do_fast_syscall_32+0x3ec/0xf9f [ 29.570876] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.575434] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.580165] ? syscall_return_slowpath+0x2ac/0x550 [ 29.585071] ? prepare_exit_to_usermode+0x350/0x350 [ 29.590063] ? sysret32_from_system_call+0x5/0x3c [ 29.594879] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.599696] entry_SYSENTER_compat+0x70/0x7f [ 29.604073] RIP: 0023:0xf7fcac99 [ 29.607408] RSP: 002b:00000000ff8331fc EFLAGS: 00000286 ORIG_RAX: 00000000000000fc [ 29.615086] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.622325] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.629565] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.636802] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.644043] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.651740] Dumping ftrace buffer: [ 29.655250] (ftrace buffer empty) [ 29.658929] Kernel Offset: disabled [ 29.662536] Rebooting in 86400 seconds..