INIT: Entering runlevel: 2 [[36minfo[39;49m] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?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 'ci-android-49-kasan-gce-2,10.128.0.61' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program syzkaller login: [ 54.994691] [ 54.995031] ===================================== [ 54.995689] [ BUG: bad unlock balance detected! ] [ 54.996355] 4.9.66-g38884cc #102 Not tainted [ 54.996955] ------------------------------------- [ 54.997594] syzkaller194966/3348 is trying to release lock (mrt_lock) at: [ 54.998594] [] ipmr_mfc_seq_stop+0xe4/0x140 [ 54.999365] but there are no more locks to release! [ 55.000025] [ 55.000025] other info that might help us debug this: [ 55.000977] 1 lock held by syzkaller194966/3348: [ 55.001604] #0: (&p->lock){+.+.+.}, at: [] seq_read+0xdd/0x1290 [ 55.002770] [ 55.002770] stack backtrace: [ 55.003367] CPU: 0 PID: 3348 Comm: syzkaller194966 Not tainted 4.9.66-g38884cc #102 [ 55.004412] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.005629] ffff8801ca7a7918 ffffffff81d90429 ffffffff849ae878 ffff8801c9c26000 [ 55.006756] ffffffff834dec54 ffffffff849ae878 ffff8801c9c26888 ffff8801ca7a7948 [ 55.007901] ffffffff812350e4 dffffc0000000000 ffffffff849ae878 00000000ffffffff [ 55.009045] Call Trace: [ 55.009401] [] dump_stack+0xc1/0x128 [ 55.010110] [] ? ipmr_mfc_seq_stop+0xe4/0x140 [ 55.010921] [] print_unlock_imbalance_bug+0x174/0x1a0 [ 55.011821] [] lock_release+0x6f8/0xb80 [ 55.012562] [] ? memcpy+0x45/0x50 [ 55.013235] [] ? ipmr_mfc_seq_stop+0xe4/0x140 [ 55.014043] [] _raw_read_unlock+0x1a/0x50 [ 55.014807] [] ipmr_mfc_seq_stop+0xe4/0x140 [ 55.020745] [] traverse+0x3a7/0x900 [ 55.025985] [] ? seq_buf_alloc+0x80/0x80 [ 55.031660] [] seq_read+0x7ea/0x1290 [ 55.036986] [] ? __lock_acquire+0x629/0x3640 [ 55.043007] [] ? seq_escape+0x200/0x200 [ 55.048593] [] ? seq_escape+0x200/0x200 [ 55.054180] [] proc_reg_read+0xef/0x170 [ 55.059779] [] ? proc_reg_write+0x170/0x170 [ 55.065713] [] __vfs_read+0x103/0x670 [ 55.071126] [] ? default_llseek+0x290/0x290 [ 55.077080] [] ? fsnotify+0x86/0xf30 [ 55.082408] [] ? fsnotify+0xf30/0xf30 [ 55.087823] [] ? avc_policy_seqno+0x9/0x20 [ 55.093670] [] ? selinux_file_permission+0x82/0x460 [ 55.100300] [] ? security_file_permission+0x89/0x1e0 [ 55.107014] [] ? rw_verify_area+0xe5/0x2b0 [ 55.112860] [] vfs_read+0x11e/0x380 [ 55.118100] [] SyS_pread64+0x13f/0x170 [ 55.123600] [] ? SyS_write+0x1b0/0x1b0 [ 55.129102] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 55.135905] [] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 55.142449] [] entry_SYSCALL_64_fastpath+0x23/0xc6 executing program