[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.60' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 28.888794] [ 28.890489] ====================================================== [ 28.896787] WARNING: possible circular locking dependency detected [ 28.903073] 4.14.209-syzkaller #0 Not tainted [ 28.907544] ------------------------------------------------------ [ 28.913844] syz-executor929/7986 is trying to acquire lock: [ 28.919523] (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 [ 28.927385] [ 28.927385] but task is already holding lock: [ 28.933324] (&iint->mutex){+.+.}, at: [] process_measurement+0x270/0xb20 [ 28.941788] [ 28.941788] which lock already depends on the new lock. [ 28.941788] [ 28.950073] [ 28.950073] the existing dependency chain (in reverse order) is: [ 28.957664] [ 28.957664] -> #1 (&iint->mutex){+.+.}: [ 28.963091] __mutex_lock+0xc4/0x1310 [ 28.967386] process_measurement+0x270/0xb20 [ 28.972286] path_openat+0x10ad/0x2970 [ 28.976662] do_filp_open+0x179/0x3c0 [ 28.980954] do_sys_open+0x296/0x410 [ 28.985157] do_syscall_64+0x1d5/0x640 [ 28.989538] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 28.995217] [ 28.995217] -> #0 (sb_writers#3){.+.+}: [ 29.000643] lock_acquire+0x170/0x3f0 [ 29.004932] __sb_start_write+0x64/0x260 [ 29.009486] mnt_want_write+0x3a/0xb0 [ 29.013791] ovl_open_maybe_copy_up+0xcf/0x130 [ 29.018873] ovl_d_real+0xbc/0x343 [ 29.022945] vfs_open+0x19e/0x220 [ 29.026890] dentry_open+0xa7/0x210 [ 29.031008] ima_calc_file_hash+0x56d/0x830 [ 29.035825] ima_collect_measurement+0x39d/0x430 [ 29.041077] process_measurement+0x78b/0xb20 [ 29.045978] path_openat+0x10ad/0x2970 [ 29.050357] do_filp_open+0x179/0x3c0 [ 29.054651] do_sys_open+0x296/0x410 [ 29.058856] do_syscall_64+0x1d5/0x640 [ 29.063236] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.068916] [ 29.068916] other info that might help us debug this: [ 29.068916] [ 29.077027] Possible unsafe locking scenario: [ 29.077027] [ 29.083052] CPU0 CPU1 [ 29.087689] ---- ---- [ 29.092324] lock(&iint->mutex); [ 29.095776] lock(sb_writers#3); [ 29.101723] lock(&iint->mutex); [ 29.107666] lock(sb_writers#3); [ 29.111093] [ 29.111093] *** DEADLOCK *** [ 29.111093] [ 29.117125] 1 lock held by syz-executor929/7986: [ 29.121877] #0: (&iint->mutex){+.+.}, at: [] process_measurement+0x270/0xb20 [ 29.130808] [ 29.130808] stack backtrace: [ 29.135281] CPU: 0 PID: 7986 Comm: syz-executor929 Not tainted 4.14.209-syzkaller #0 [ 29.143163] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.152498] Call Trace: [ 29.155059] dump_stack+0x1b2/0x283 [ 29.158661] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 29.164430] __lock_acquire+0x2e0e/0x3f20 [ 29.168553] ? kmem_cache_alloc+0x124/0x3c0 [ 29.172850] ? trace_hardirqs_on+0x10/0x10 [ 29.177059] ? trace_hardirqs_on+0x10/0x10 [ 29.181263] ? do_filp_open+0x179/0x3c0 [ 29.185210] ? do_syscall_64+0x1d5/0x640 [ 29.189244] ? entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.194579] ? __lock_acquire+0x5fc/0x3f20 [ 29.198785] ? trace_hardirqs_on+0x10/0x10 [ 29.202995] ? fs_reclaim_release+0xd0/0x110 [ 29.207391] lock_acquire+0x170/0x3f0 [ 29.211164] ? mnt_want_write+0x3a/0xb0 [ 29.215117] __sb_start_write+0x64/0x260 [ 29.219165] ? mnt_want_write+0x3a/0xb0 [ 29.223118] mnt_want_write+0x3a/0xb0 [ 29.226895] ovl_open_maybe_copy_up+0xcf/0x130 [ 29.231468] ovl_d_real+0xbc/0x343 [ 29.234981] vfs_open+0x19e/0x220 [ 29.238469] dentry_open+0xa7/0x210 [ 29.242074] ima_calc_file_hash+0x56d/0x830 [ 29.246412] ? ext4_xattr_get+0x139/0x8b0 [ 29.250538] ima_collect_measurement+0x39d/0x430 [ 29.255312] ? ima_get_action+0x70/0x70 [ 29.259264] ? vfs_getxattr_alloc+0xc8/0x2d0 [ 29.263644] ? ima_get_cache_status+0x170/0x170 [ 29.268285] process_measurement+0x78b/0xb20 [ 29.272668] ? ima_rdwr_violation_check+0x3a0/0x3a0 [ 29.277656] ? generic_file_open+0x68/0x90 [ 29.281862] ? ext4_release_file+0x2d0/0x2d0 [ 29.286243] ? apparmor_file_alloc_security+0x800/0x800 [ 29.291576] ? lock_downgrade+0x740/0x740 [ 29.295709] ? file_ra_state_init+0xc4/0x1e0 [ 29.300134] ? do_dentry_open+0x698/0xec0 [ 29.304252] ? ext4_release_file+0x2d0/0x2d0 [ 29.308633] ? vfs_open+0x10d/0x220 [ 29.312236] path_openat+0x10ad/0x2970 [ 29.316096] ? path_lookupat+0x780/0x780 [ 29.320133] ? trace_hardirqs_on+0x10/0x10 [ 29.324341] ? trace_hardirqs_on+0x10/0x10 [ 29.328560] do_filp_open+0x179/0x3c0 [ 29.332334] ? may_open_dev+0xe0/0xe0 [ 29.336108] ? lock_downgrade+0x740/0x740 [ 29.340231] ? do_raw_spin_unlock+0x164/0x220 [ 29.344698] ? _raw_spin_unlock+0x29/0x40 [ 29.348840] ? __alloc_fd+0x1be/0x490 [ 29.352614] ? _raw_spin_unlock_irq+0x24/0x80 [ 29.357079] do_sys_open+0x296/0x410 [ 29.360763] ? filp_open+0x60/0x60 [ 29.364276] ? do_syscall_64+0x4c/0x640 [ 29.368223] ? do_sys_open+0x410/0x410 [ 29.372081] do_syscall_64+0x1d5/0x640 [ 29.375943] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.381124] RIP: 0033:0x440399 [ 29.384285] RSP: 002b:00007ffdf3a95ec8 EFLAGS: 00000246 ORIG_RAX: 00000000