[....] Starting enhanced syslogd: rsyslogd[ 10.770622] audit: type=1400 audit(1514808247.560:4): avc: denied { syslog } for pid=3176 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[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.55' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 19.625131] [ 19.625465] ===================================== [ 19.626106] [ BUG: bad unlock balance detected! ] [ 19.626766] 4.9.73-gf3f3457 #11 Not tainted [ 19.627336] ------------------------------------- [ 19.627973] syzkaller464528/3442 is trying to release lock (mrt_lock) at: [ 19.629031] [] ipmr_mfc_seq_stop+0xe4/0x140 [ 19.629803] but there are no more locks to release! [ 19.630475] [ 19.630475] other info that might help us debug this: [ 19.631349] 1 lock held by syzkaller464528/3442: [ 19.631975] #0: (&p->lock){+.+.+.}, at: [] seq_read+0xdd/0x1290 [ 19.633139] [ 19.633139] stack backtrace: [ 19.633735] CPU: 1 PID: 3442 Comm: syzkaller464528 Not tainted 4.9.73-gf3f3457 #11 [ 19.634740] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 19.635960] ffff8801c85a7878 ffffffff81d922b9 ffffffff849b0638 ffff8801c850e000 [ 19.637088] ffffffff834e5174 ffffffff849b0638 ffff8801c850e888 ffff8801c85a78a8 [ 19.638215] ffffffff81235fa4 dffffc0000000000 ffffffff849b0638 00000000ffffffff [ 19.639371] Call Trace: [ 19.639744] [] dump_stack+0xc1/0x128 [ 19.640451] [] ? ipmr_mfc_seq_stop+0xe4/0x140 [ 19.641267] [] print_unlock_imbalance_bug+0x174/0x1a0 [ 19.642163] [] lock_release+0x6f8/0xb80 [ 19.642907] [] ? memcpy+0x45/0x50 [ 19.643596] [] ? ipmr_mfc_seq_stop+0xe4/0x140 [ 19.644405] [] _raw_read_unlock+0x1a/0x50 [ 19.645182] [] ipmr_mfc_seq_stop+0xe4/0x140 [ 19.650834] [] traverse+0x3a7/0x900 [ 19.656082] [] ? seq_buf_alloc+0x80/0x80 [ 19.661759] [] seq_read+0x7ea/0x1290 [ 19.667089] [] ? __lock_acquire+0x629/0x3640 [ 19.673110] [] ? seq_escape+0x200/0x200 [ 19.678697] [] ? seq_escape+0x200/0x200 [ 19.684290] [] proc_reg_read+0xef/0x170 [ 19.689880] [] ? proc_reg_write+0x170/0x170 [ 19.695820] [] __vfs_read+0x103/0x670 [ 19.701232] [] ? default_llseek+0x290/0x290 [ 19.707169] [] ? fsnotify+0x86/0xf30 [ 19.712495] [] ? fsnotify+0xf30/0xf30 [ 19.717914] [] ? avc_policy_seqno+0x9/0x20 [ 19.723761] [] ? selinux_file_permission+0x82/0x460 [ 19.730391] [] ? security_file_permission+0x89/0x1e0 [ 19.737107] [] ? rw_verify_area+0xe5/0x2b0 [ 19.742954] [] vfs_read+0x11e/0x380 [ 19.748195] [] SyS_pread64+0x13f/0x170 [ 19.753696] [] ? SyS_write+0x1b0/0x1b0 [ 19.759200] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 19.765483] [] sys32_pread+0x39/0x50 executing program [ 19.770808] [] ? sys32_waitpid+0x30/0x30 [ 19.776482] [] do_fast_syscall_32+0x2f7/0x890 [ 19.782587] [] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 19.789217] [] entry_SYSENTER_compat+0x51/0x60 executing program executing program