Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.54' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 26.180138] [ 26.181774] ====================================================== [ 26.188070] WARNING: possible circular locking dependency detected [ 26.194447] 4.14.298-syzkaller #0 Not tainted [ 26.198908] ------------------------------------------------------ [ 26.205196] syz-executor269/7982 is trying to acquire lock: [ 26.210881] (sb_writers#3){.+.+}, at: [] mnt_want_write+0x3a/0xb0 [ 26.218744] [ 26.218744] but task is already holding lock: [ 26.224688] (&iint->mutex){+.+.}, at: [] process_measurement+0x270/0xb20 [ 26.233159] [ 26.233159] which lock already depends on the new lock. [ 26.233159] [ 26.241449] [ 26.241449] the existing dependency chain (in reverse order) is: [ 26.249053] [ 26.249053] -> #1 (&iint->mutex){+.+.}: [ 26.254492] __mutex_lock+0xc4/0x1310 [ 26.258798] process_measurement+0x270/0xb20 [ 26.263707] path_openat+0x10ad/0x2970 [ 26.268101] do_filp_open+0x179/0x3c0 [ 26.272399] do_sys_open+0x296/0x410 [ 26.276789] do_syscall_64+0x1d5/0x640 [ 26.281176] entry_SYSCALL_64_after_hwframe+0x5e/0xd3 [ 26.286855] [ 26.286855] -> #0 (sb_writers#3){.+.+}: [ 26.292286] lock_acquire+0x170/0x3f0 [ 26.296585] __sb_start_write+0x64/0x260 [ 26.301144] mnt_want_write+0x3a/0xb0 [ 26.305443] ovl_open_maybe_copy_up+0xcf/0x130 [ 26.310531] ovl_d_real+0xbc/0x350 [ 26.314565] vfs_open+0x19e/0x220 [ 26.318514] dentry_open+0xa7/0x210 [ 26.322642] ima_calc_file_hash+0x51c/0x780 [ 26.327463] ima_collect_measurement+0x39d/0x430 [ 26.332712] process_measurement+0x78b/0xb20 [ 26.337646] path_openat+0x10ad/0x2970 [ 26.342027] do_filp_open+0x179/0x3c0 [ 26.346329] do_sys_open+0x296/0x410 [ 26.350544] do_syscall_64+0x1d5/0x640 [ 26.354928] entry_SYSCALL_64_after_hwframe+0x5e/0xd3 [ 26.360614] [ 26.360614] other info that might help us debug this: [ 26.360614] [ 26.368728] Possible unsafe locking scenario: [ 26.368728] [ 26.374758] CPU0 CPU1 [ 26.379404] ---- ---- [ 26.384043] lock(&iint->mutex); [ 26.387468] lock(sb_writers#3); [ 26.393412] lock(&iint->mutex); [ 26.399354] lock(sb_writers#3); [ 26.402779] [ 26.402779] *** DEADLOCK *** [ 26.402779] [ 26.408811] 1 lock held by syz-executor269/7982: [ 26.413533] #0: (&iint->mutex){+.+.}, at: [] process_measurement+0x270/0xb20 [ 26.422442] [ 26.422442] stack backtrace: [ 26.426918] CPU: 1 PID: 7982 Comm: syz-executor269 Not tainted 4.14.298-syzkaller #0 [ 26.434783] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 [ 26.444111] Call Trace: [ 26.446679] dump_stack+0x1b2/0x281 [ 26.450282] print_circular_bug.constprop.0.cold+0x2d7/0x41e [ 26.456052] __lock_acquire+0x2e0e/0x3f20 [ 26.460177] ? kmem_cache_alloc+0x124/0x3c0 [ 26.464469] ? trace_hardirqs_on+0x10/0x10 [ 26.468678] ? trace_hardirqs_on+0x10/0x10 [ 26.472885] ? do_filp_open+0x179/0x3c0 [ 26.476832] ? do_syscall_64+0x1d5/0x640 [ 26.480872] ? entry_SYSCALL_64_after_hwframe+0x5e/0xd3 [ 26.486209] ? __lock_acquire+0x5fc/0x3f20 [ 26.490415] ? trace_hardirqs_on+0x10/0x10 [ 26.494623] ? fs_reclaim_release+0xd0/0x110 [ 26.499005] lock_acquire+0x170/0x3f0 [ 26.502778] ? mnt_want_write+0x3a/0xb0 [ 26.506727] __sb_start_write+0x64/0x260 [ 26.510760] ? mnt_want_write+0x3a/0xb0 [ 26.514706] mnt_want_write+0x3a/0xb0 [ 26.518482] ovl_open_maybe_copy_up+0xcf/0x130 [ 26.523053] ovl_d_real+0xbc/0x350 [ 26.526569] vfs_open+0x19e/0x220 [ 26.529996] dentry_open+0xa7/0x210 [ 26.533614] ima_calc_file_hash+0x51c/0x780 [ 26.537910] ? ext4_xattr_get+0x139/0x8b0 [ 26.542034] ima_collect_measurement+0x39d/0x430 [ 26.546762] ? ima_get_action+0x70/0x70 [ 26.550709] ? vfs_getxattr_alloc+0xc8/0x2d0 [ 26.555090] ? ima_get_cache_status+0x170/0x170 [ 26.559733] process_measurement+0x78b/0xb20 [ 26.564116] ? ima_rdwr_violation_check+0x3a0/0x3a0 [ 26.569104] ? generic_file_open+0x68/0x90 [ 26.573312] ? ext4_release_file+0x2d0/0x2d0 [ 26.577692] ? apparmor_file_alloc_security+0x800/0x800 [ 26.583037] ? lock_downgrade+0x740/0x740 [ 26.587159] ? file_ra_state_init+0xc4/0x1e0 [ 26.591536] ? do_dentry_open+0x698/0xec0 [ 26.595654] ? ext4_release_file+0x2d0/0x2d0 [ 26.600048] ? vfs_open+0x10d/0x220 [ 26.603650] path_openat+0x10ad/0x2970 [ 26.607509] ? path_lookupat+0x780/0x780 [ 26.611542] ? trace_hardirqs_on+0x10/0x10 [ 26.615755] ? trace_hardirqs_on+0x10/0x10 [ 26.619963] do_filp_open+0x179/0x3c0 [ 26.623738] ? may_open_dev+0xe0/0xe0 [ 26.627513] ? lock_downgrade+0x740/0x740 [ 26