[....] Starting enhanced syslogd: rsyslogd[ 18.148865] audit: type=1400 audit(1520868249.383:5): avc: denied { syslog } for pid=4120 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: [ 22.553687] audit: type=1400 audit(1520868253.788:6): avc: denied { map } for pid=4261 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 '10.128.0.44' (ECDSA) to the list of known hosts. [ 28.908799] audit: type=1400 audit(1520868260.143:7): avc: denied { map } for pid=4275 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 2018/03/12 15:24:20 parsed 1 programs 2018/03/12 15:24:20 executed programs: 0 [ 29.164842] audit: type=1400 audit(1520868260.399:8): avc: denied { map } for pid=4275 comm="syz-execprog" path="/root/syzkaller-shm511213081" 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 [ 29.177705] IPVS: ftp: loaded support on port[0] = 21 [ 29.224354] ================================================================== [ 29.231788] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 29.237907] Read of size 8 at addr ffff8801b4b77740 by task syz-executor0/4283 [ 29.245234] [ 29.246836] CPU: 1 PID: 4283 Comm: syz-executor0 Not tainted 4.16.0-rc5+ #261 [ 29.254078] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.263408] Call Trace: [ 29.266005] dump_stack+0x194/0x24d [ 29.269608] ? arch_local_irq_restore+0x53/0x53 [ 29.274249] ? show_regs_print_info+0x18/0x18 [ 29.278717] ? save_stack+0xa3/0xd0 [ 29.282327] ? ucma_close+0x2d7/0x2f0 [ 29.286101] print_address_description+0x73/0x250 [ 29.290917] ? ucma_close+0x2d7/0x2f0 [ 29.294700] kasan_report+0x23c/0x360 [ 29.298478] __asan_report_load8_noabort+0x14/0x20 [ 29.303387] ucma_close+0x2d7/0x2f0 [ 29.306995] ? __might_sleep+0x95/0x190 [ 29.310944] ? ucma_free_ctx+0xd90/0xd90 [ 29.314980] __fput+0x327/0x7e0 [ 29.318247] ? fput+0x140/0x140 [ 29.321540] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.326023] ____fput+0x15/0x20 [ 29.329289] task_work_run+0x199/0x270 [ 29.333154] ? task_work_cancel+0x210/0x210 [ 29.337453] ? _raw_spin_unlock+0x22/0x30 [ 29.341583] ? switch_task_namespaces+0x87/0xc0 [ 29.346231] do_exit+0x9bb/0x1ad0 [ 29.349660] ? ucma_create_id+0x45b/0x620 [ 29.353789] ? mm_update_next_owner+0x930/0x930 [ 29.358445] ? ucma_create_id+0x17b/0x620 [ 29.362572] ? ucma_get_event+0xa90/0xa90 [ 29.366707] ? __might_sleep+0x95/0x190 [ 29.371208] ? kasan_check_write+0x14/0x20 [ 29.375422] ? _copy_from_user+0x99/0x110 [ 29.379548] ? ucma_write+0x11f/0x3d0 [ 29.383327] ? ucma_get_event+0xa90/0xa90 [ 29.387454] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.391931] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.396405] ? __vfs_write+0xf7/0x970 [ 29.400191] ? rcu_note_context_switch+0x710/0x710 [ 29.405098] ? kernel_read+0x120/0x120 [ 29.408968] ? __might_sleep+0x95/0x190 [ 29.412930] ? _cond_resched+0x14/0x30 [ 29.416794] ? __inode_security_revalidate+0xd9/0x130 [ 29.421971] ? avc_policy_seqno+0x9/0x20 [ 29.426012] ? security_file_permission+0x89/0x1e0 [ 29.430930] ? compat_SyS_futex+0x288/0x380 [ 29.435226] ? vfs_write+0x224/0x510 [ 29.438919] do_group_exit+0x149/0x400 [ 29.442782] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.447943] ? SyS_write+0x184/0x220 [ 29.451633] ? __do_page_fault+0x3d6/0xc90 [ 29.455850] ? SyS_exit+0x30/0x30 [ 29.459278] ? SyS_read+0x220/0x220 [ 29.462886] ? do_fast_syscall_32+0x156/0xf9f [ 29.467356] ? do_group_exit+0x400/0x400 [ 29.471393] SyS_exit_group+0x1d/0x20 [ 29.475177] do_fast_syscall_32+0x3ec/0xf9f [ 29.479485] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.484041] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.488787] ? syscall_return_slowpath+0x2ac/0x550 [ 29.493698] ? prepare_exit_to_usermode+0x350/0x350 [ 29.498695] ? sysret32_from_system_call+0x5/0x3c [ 29.503536] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.508360] entry_SYSENTER_compat+0x70/0x7f [ 29.512740] RIP: 0023:0xf7feac99 [ 29.516079] RSP: 002b:00000000ffd4f82c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.523756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.530997] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.538244] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.545485] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.552726] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.559983] [ 29.561584] Allocated by task 4283: [ 29.565190] save_stack+0x43/0xd0 [ 29.568618] kasan_kmalloc+0xad/0xe0 [ 29.572305] kmem_cache_alloc_trace+0x136/0x740 [ 29.576946] ucma_alloc_ctx+0xce/0x610 [ 29.580801] ucma_create_id+0x205/0x620 [ 29.584749] ucma_write+0x2d6/0x3d0 [ 29.588346] __vfs_write+0xef/0x970 [ 29.591950] vfs_write+0x189/0x510 [ 29.595469] SyS_write+0xef/0x220 [ 29.598897] do_fast_syscall_32+0x3ec/0xf9f [ 29.603191] entry_SYSENTER_compat+0x70/0x7f [ 29.607569] [ 29.609167] Freed by task 4283: [ 29.612417] save_stack+0x43/0xd0 [ 29.615841] __kasan_slab_free+0x11a/0x170 [ 29.620047] kasan_slab_free+0xe/0x10 [ 29.623828] kfree+0xd9/0x260 [ 29.626912] ucma_create_id+0x45b/0x620 [ 29.630861] ucma_write+0x2d6/0x3d0 [ 29.634462] __vfs_write+0xef/0x970 [ 29.638062] vfs_write+0x189/0x510 [ 29.641572] SyS_write+0xef/0x220 [ 29.644996] do_fast_syscall_32+0x3ec/0xf9f [ 29.649289] entry_SYSENTER_compat+0x70/0x7f [ 29.653665] [ 29.655266] The buggy address belongs to the object at ffff8801b4b776c0 [ 29.655266] which belongs to the cache kmalloc-256 of size 256 [ 29.667911] The buggy address is located 128 bytes inside of [ 29.667911] 256-byte region [ffff8801b4b776c0, ffff8801b4b777c0) [ 29.679758] The buggy address belongs to the page: [ 29.684671] page:ffffea0006d2ddc0 count:1 mapcount:0 mapping:ffff8801b4b77080 index:0xffff8801b4b771c0 [ 29.694101] flags: 0x2fffc0000000100(slab) [ 29.698324] raw: 02fffc0000000100 ffff8801b4b77080 ffff8801b4b771c0 000000010000000b [ 29.706187] raw: ffffea0006cd7f60 ffffea00072efa20 ffff8801dac007c0 0000000000000000 [ 29.714049] page dumped because: kasan: bad access detected [ 29.719747] [ 29.721357] Memory state around the buggy address: [ 29.726264] ffff8801b4b77600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc [ 29.733604] ffff8801b4b77680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.740942] >ffff8801b4b77700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.748278] ^ [ 29.753706] ffff8801b4b77780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 29.761042] ffff8801b4b77800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.768376] ================================================================== [ 29.775710] Disabling lock debugging due to kernel taint [ 29.781238] Kernel panic - not syncing: panic_on_warn set ... [ 29.781238] [ 29.788588] CPU: 1 PID: 4283 Comm: syz-executor0 Tainted: G B 4.16.0-rc5+ #261 [ 29.797135] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.806474] Call Trace: [ 29.809046] dump_stack+0x194/0x24d [ 29.812653] ? arch_local_irq_restore+0x53/0x53 [ 29.817304] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.822041] ? vsnprintf+0x1ed/0x1900 [ 29.825824] ? ucma_close+0x240/0x2f0 [ 29.829606] panic+0x1e4/0x41c [ 29.832769] ? refcount_error_report+0x214/0x214 [ 29.837494] ? add_taint+0x1c/0x50 [ 29.841006] ? add_taint+0x1c/0x50 [ 29.844522] ? ucma_close+0x2d7/0x2f0 [ 29.848294] kasan_end_report+0x50/0x50 [ 29.852236] kasan_report+0x149/0x360 [ 29.856009] __asan_report_load8_noabort+0x14/0x20 [ 29.860912] ucma_close+0x2d7/0x2f0 [ 29.864508] ? __might_sleep+0x95/0x190 [ 29.868452] ? ucma_free_ctx+0xd90/0xd90 [ 29.872481] __fput+0x327/0x7e0 [ 29.875733] ? fput+0x140/0x140 [ 29.878982] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.883450] ____fput+0x15/0x20 [ 29.886701] task_work_run+0x199/0x270 [ 29.890559] ? task_work_cancel+0x210/0x210 [ 29.894851] ? _raw_spin_unlock+0x22/0x30 [ 29.899142] ? switch_task_namespaces+0x87/0xc0 [ 29.903803] do_exit+0x9bb/0x1ad0 [ 29.907228] ? ucma_create_id+0x45b/0x620 [ 29.911350] ? mm_update_next_owner+0x930/0x930 [ 29.915986] ? ucma_create_id+0x17b/0x620 [ 29.920103] ? ucma_get_event+0xa90/0xa90 [ 29.924229] ? __might_sleep+0x95/0x190 [ 29.928174] ? kasan_check_write+0x14/0x20 [ 29.932379] ? _copy_from_user+0x99/0x110 [ 29.936495] ? ucma_write+0x11f/0x3d0 [ 29.940264] ? ucma_get_event+0xa90/0xa90 [ 29.944380] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.948853] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.953319] ? __vfs_write+0xf7/0x970 [ 29.957097] ? rcu_note_context_switch+0x710/0x710 [ 29.961998] ? kernel_read+0x120/0x120 [ 29.965860] ? __might_sleep+0x95/0x190 [ 29.969808] ? _cond_resched+0x14/0x30 [ 29.973665] ? __inode_security_revalidate+0xd9/0x130 [ 29.978824] ? avc_policy_seqno+0x9/0x20 [ 29.982858] ? security_file_permission+0x89/0x1e0 [ 29.987766] ? compat_SyS_futex+0x288/0x380 [ 29.992058] ? vfs_write+0x224/0x510 [ 29.995747] do_group_exit+0x149/0x400 [ 29.999606] ? compat_SyS_get_robust_list+0x300/0x300 [ 30.004762] ? SyS_write+0x184/0x220 [ 30.008455] ? __do_page_fault+0x3d6/0xc90 [ 30.012660] ? SyS_exit+0x30/0x30 [ 30.016084] ? SyS_read+0x220/0x220 [ 30.019683] ? do_fast_syscall_32+0x156/0xf9f [ 30.024147] ? do_group_exit+0x400/0x400 [ 30.028179] SyS_exit_group+0x1d/0x20 [ 30.031952] do_fast_syscall_32+0x3ec/0xf9f [ 30.036247] ? do_int80_syscall_32+0x9c0/0x9c0 [ 30.040796] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 30.045522] ? syscall_return_slowpath+0x2ac/0x550 [ 30.050426] ? prepare_exit_to_usermode+0x350/0x350 [ 30.055425] ? sysret32_from_system_call+0x5/0x3c [ 30.060239] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 30.065052] entry_SYSENTER_compat+0x70/0x7f [ 30.069435] RIP: 0023:0xf7feac99 [ 30.072769] RSP: 002b:00000000ffd4f82c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 30.080443] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 30.087685] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 30.094929] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 30.102174] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 30.109421] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 30.117092] Dumping ftrace buffer: [ 30.120608] (ftrace buffer empty) [ 30.124297] Kernel Offset: disabled [ 30.127906] Rebooting in 86400 seconds..