[....] Starting enhanced syslogd: rsyslogd[ 17.021941] audit: type=1400 audit(1521073294.465:5): avc: denied { syslog } for pid=4082 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: [ 22.048862] audit: type=1400 audit(1521073299.492:6): avc: denied { map } for pid=4220 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 '10.128.0.20' (ECDSA) to the list of known hosts. [ 28.566698] audit: type=1400 audit(1521073306.010:7): avc: denied { map } for pid=4236 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 2018/03/15 00:21:46 parsed 1 programs 2018/03/15 00:21:46 executed programs: 0 [ 28.815470] audit: type=1400 audit(1521073306.257:8): avc: denied { map } for pid=4236 comm="syz-execprog" path="/root/syzkaller-shm846333201" 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 [ 28.827778] IPVS: ftp: loaded support on port[0] = 21 [ 28.871808] ================================================================== [ 28.879218] BUG: KASAN: use-after-free in ucma_close+0x2d7/0x2f0 [ 28.885339] Read of size 8 at addr ffff8801af0439c0 by task syz-executor0/4244 [ 28.892663] [ 28.894263] CPU: 1 PID: 4244 Comm: syz-executor0 Not tainted 4.16.0-rc5+ #263 [ 28.901502] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.910830] Call Trace: [ 28.913390] dump_stack+0x194/0x24d [ 28.916997] ? arch_local_irq_restore+0x53/0x53 [ 28.921641] ? show_regs_print_info+0x18/0x18 [ 28.926108] ? save_stack+0xa3/0xd0 [ 28.929709] ? ucma_close+0x2d7/0x2f0 [ 28.933481] print_address_description+0x73/0x250 [ 28.938296] ? ucma_close+0x2d7/0x2f0 [ 28.942069] kasan_report+0x23c/0x360 [ 28.945847] __asan_report_load8_noabort+0x14/0x20 [ 28.950747] ucma_close+0x2d7/0x2f0 [ 28.954344] ? __might_sleep+0x95/0x190 [ 28.958297] ? ucma_free_ctx+0xd90/0xd90 [ 28.962329] __fput+0x327/0x7e0 [ 28.965586] ? fput+0x140/0x140 [ 28.968840] ? _raw_spin_unlock_irq+0x27/0x70 [ 28.973311] ____fput+0x15/0x20 [ 28.976560] task_work_run+0x199/0x270 [ 28.980424] ? task_work_cancel+0x210/0x210 [ 28.984717] ? _raw_spin_unlock+0x22/0x30 [ 28.988839] ? switch_task_namespaces+0x87/0xc0 [ 28.993483] do_exit+0x9bb/0x1ad0 [ 28.996908] ? ucma_create_id+0x45b/0x620 [ 29.001038] ? mm_update_next_owner+0x930/0x930 [ 29.005683] ? ucma_create_id+0x17b/0x620 [ 29.009802] ? ucma_get_event+0xa90/0xa90 [ 29.013938] ? __might_sleep+0x95/0x190 [ 29.017895] ? kasan_check_write+0x14/0x20 [ 29.022103] ? _copy_from_user+0x99/0x110 [ 29.026225] ? ucma_write+0x11f/0x3d0 [ 29.029994] ? ucma_get_event+0xa90/0xa90 [ 29.034128] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.038608] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.043078] ? __vfs_write+0xf7/0x970 [ 29.046849] ? rcu_note_context_switch+0x710/0x710 [ 29.051750] ? kernel_read+0x120/0x120 [ 29.055608] ? __might_sleep+0x95/0x190 [ 29.059557] ? _cond_resched+0x14/0x30 [ 29.063417] ? __inode_security_revalidate+0xd9/0x130 [ 29.068578] ? avc_policy_seqno+0x9/0x20 [ 29.072626] ? security_file_permission+0x89/0x1e0 [ 29.077539] ? compat_SyS_futex+0x288/0x380 [ 29.081834] ? vfs_write+0x224/0x510 [ 29.085522] do_group_exit+0x149/0x400 [ 29.089389] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.094551] ? SyS_write+0x184/0x220 [ 29.098235] ? __do_page_fault+0x3d6/0xc90 [ 29.102440] ? SyS_exit+0x30/0x30 [ 29.105866] ? SyS_read+0x220/0x220 [ 29.109467] ? do_fast_syscall_32+0x156/0xf9f [ 29.113934] ? do_group_exit+0x400/0x400 [ 29.117966] SyS_exit_group+0x1d/0x20 [ 29.121738] do_fast_syscall_32+0x3ec/0xf9f [ 29.126041] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.130600] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.135331] ? syscall_return_slowpath+0x2ac/0x550 [ 29.140233] ? prepare_exit_to_usermode+0x350/0x350 [ 29.145227] ? sysret32_from_system_call+0x5/0x3c [ 29.150055] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.154877] entry_SYSENTER_compat+0x70/0x7f [ 29.159255] RIP: 0023:0xf7fdec99 [ 29.162588] RSP: 002b:00000000ffd6b02c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.170266] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.177504] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.184744] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.191982] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.199225] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.206481] [ 29.208081] Allocated by task 4244: [ 29.211682] save_stack+0x43/0xd0 [ 29.215105] kasan_kmalloc+0xad/0xe0 [ 29.218794] kmem_cache_alloc_trace+0x136/0x740 [ 29.223438] ucma_alloc_ctx+0xce/0x610 [ 29.227294] ucma_create_id+0x205/0x620 [ 29.231243] ucma_write+0x2d6/0x3d0 [ 29.234845] __vfs_write+0xef/0x970 [ 29.238440] vfs_write+0x189/0x510 [ 29.241947] SyS_write+0xef/0x220 [ 29.245380] do_fast_syscall_32+0x3ec/0xf9f [ 29.249677] entry_SYSENTER_compat+0x70/0x7f [ 29.254063] [ 29.255660] Freed by task 4244: [ 29.258908] save_stack+0x43/0xd0 [ 29.262328] __kasan_slab_free+0x11a/0x170 [ 29.266530] kasan_slab_free+0xe/0x10 [ 29.270305] kfree+0xd9/0x260 [ 29.273386] ucma_create_id+0x45b/0x620 [ 29.277328] ucma_write+0x2d6/0x3d0 [ 29.280924] __vfs_write+0xef/0x970 [ 29.284519] vfs_write+0x189/0x510 [ 29.288031] SyS_write+0xef/0x220 [ 29.291455] do_fast_syscall_32+0x3ec/0xf9f [ 29.295745] entry_SYSENTER_compat+0x70/0x7f [ 29.300122] [ 29.301723] The buggy address belongs to the object at ffff8801af043940 [ 29.301723] which belongs to the cache kmalloc-256 of size 256 [ 29.314346] The buggy address is located 128 bytes inside of [ 29.314346] 256-byte region [ffff8801af043940, ffff8801af043a40) [ 29.326188] The buggy address belongs to the page: [ 29.331091] page:ffffea0006bc10c0 count:1 mapcount:0 mapping:ffff8801af043080 index:0x0 [ 29.339201] flags: 0x2fffc0000000100(slab) [ 29.343406] raw: 02fffc0000000100 ffff8801af043080 0000000000000000 000000010000000c [ 29.351257] raw: ffffea0006d51ce0 ffffea0006b7bea0 ffff8801dac007c0 0000000000000000 [ 29.359109] page dumped because: kasan: bad access detected [ 29.364791] [ 29.366388] Memory state around the buggy address: [ 29.371287] ffff8801af043880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 29.378622] ffff8801af043900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 29.385949] >ffff8801af043980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.393511] ^ [ 29.398931] ffff8801af043a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 29.406260] ffff8801af043a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.413584] ================================================================== [ 29.420912] Disabling lock debugging due to kernel taint [ 29.426635] Kernel panic - not syncing: panic_on_warn set ... [ 29.426635] [ 29.433980] CPU: 1 PID: 4244 Comm: syz-executor0 Tainted: G B 4.16.0-rc5+ #263 [ 29.442522] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.451841] Call Trace: [ 29.454399] dump_stack+0x194/0x24d [ 29.457995] ? arch_local_irq_restore+0x53/0x53 [ 29.462637] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.467369] ? vsnprintf+0x1ed/0x1900 [ 29.471140] ? ucma_close+0x210/0x2f0 [ 29.474908] panic+0x1e4/0x41c [ 29.478073] ? refcount_error_report+0x214/0x214 [ 29.482799] ? add_taint+0x1c/0x50 [ 29.486311] ? add_taint+0x1c/0x50 [ 29.489822] ? ucma_close+0x2d7/0x2f0 [ 29.493591] kasan_end_report+0x50/0x50 [ 29.497533] kasan_report+0x149/0x360 [ 29.501304] __asan_report_load8_noabort+0x14/0x20 [ 29.506200] ucma_close+0x2d7/0x2f0 [ 29.509798] ? __might_sleep+0x95/0x190 [ 29.513739] ? ucma_free_ctx+0xd90/0xd90 [ 29.517770] __fput+0x327/0x7e0 [ 29.521026] ? fput+0x140/0x140 [ 29.524277] ? _raw_spin_unlock_irq+0x27/0x70 [ 29.528741] ____fput+0x15/0x20 [ 29.531987] task_work_run+0x199/0x270 [ 29.535847] ? task_work_cancel+0x210/0x210 [ 29.540136] ? _raw_spin_unlock+0x22/0x30 [ 29.544252] ? switch_task_namespaces+0x87/0xc0 [ 29.548889] do_exit+0x9bb/0x1ad0 [ 29.552310] ? ucma_create_id+0x45b/0x620 [ 29.556431] ? mm_update_next_owner+0x930/0x930 [ 29.561070] ? ucma_create_id+0x17b/0x620 [ 29.565187] ? ucma_get_event+0xa90/0xa90 [ 29.569309] ? __might_sleep+0x95/0x190 [ 29.573253] ? kasan_check_write+0x14/0x20 [ 29.577465] ? _copy_from_user+0x99/0x110 [ 29.581582] ? ucma_write+0x11f/0x3d0 [ 29.585353] ? ucma_get_event+0xa90/0xa90 [ 29.589467] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.593933] ? ucma_resolve_route+0x1a0/0x1a0 [ 29.598397] ? __vfs_write+0xf7/0x970 [ 29.602165] ? rcu_note_context_switch+0x710/0x710 [ 29.607065] ? kernel_read+0x120/0x120 [ 29.610920] ? __might_sleep+0x95/0x190 [ 29.614863] ? _cond_resched+0x14/0x30 [ 29.618721] ? __inode_security_revalidate+0xd9/0x130 [ 29.623882] ? avc_policy_seqno+0x9/0x20 [ 29.627914] ? security_file_permission+0x89/0x1e0 [ 29.632816] ? compat_SyS_futex+0x288/0x380 [ 29.637102] ? vfs_write+0x224/0x510 [ 29.640792] do_group_exit+0x149/0x400 [ 29.644647] ? compat_SyS_get_robust_list+0x300/0x300 [ 29.649802] ? SyS_write+0x184/0x220 [ 29.653484] ? __do_page_fault+0x3d6/0xc90 [ 29.657685] ? SyS_exit+0x30/0x30 [ 29.661108] ? SyS_read+0x220/0x220 [ 29.664707] ? do_fast_syscall_32+0x156/0xf9f [ 29.669172] ? do_group_exit+0x400/0x400 [ 29.673200] SyS_exit_group+0x1d/0x20 [ 29.676967] do_fast_syscall_32+0x3ec/0xf9f [ 29.681259] ? do_int80_syscall_32+0x9c0/0x9c0 [ 29.685811] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 29.690536] ? syscall_return_slowpath+0x2ac/0x550 [ 29.695435] ? prepare_exit_to_usermode+0x350/0x350 [ 29.700422] ? sysret32_from_system_call+0x5/0x3c [ 29.705233] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 29.710045] entry_SYSENTER_compat+0x70/0x7f [ 29.714422] RIP: 0023:0xf7fdec99 [ 29.717752] RSP: 002b:00000000ffd6b02c EFLAGS: 00000282 ORIG_RAX: 00000000000000fc [ 29.725428] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000000 [ 29.732664] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 29.739904] RBP: 00000000080a2c25 R08: 0000000000000000 R09: 0000000000000000 [ 29.747144] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 29.754380] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.762022] Dumping ftrace buffer: [ 29.765530] (ftrace buffer empty) [ 29.769209] Kernel Offset: disabled [ 29.772806] Rebooting in 86400 seconds..