====================================================== WARNING: possible circular locking dependency detected 6.3.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/8699 is trying to acquire lock: ffff88802bd8b860 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7c0/0x1ce0 security/integrity/ima/ima_main.c:262 but task is already holding lock: ffff88814b7e4460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:394 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sb_writers#4){.+.+}-{0:0}: lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1477 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1552 mnt_want_write+0x3f/0x90 fs/namespace.c:394 ovl_maybe_copy_up+0x115/0x180 fs/overlayfs/copy_up.c:1125 ovl_open+0x10c/0x2b0 fs/overlayfs/file.c:153 do_dentry_open+0x7f9/0x10f0 fs/open.c:920 vfs_open fs/open.c:1051 [inline] dentry_open+0xc5/0x120 fs/open.c:1067 ima_calc_file_hash+0x15d/0x1c00 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x3a7/0x880 security/integrity/ima/ima_api.c:293 process_measurement+0xfdb/0x1ce0 security/integrity/ima/ima_main.c:341 ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:539 do_open fs/namei.c:3562 [inline] path_openat+0x280a/0x3170 fs/namei.c:3715 do_filp_open+0x234/0x490 fs/namei.c:3742 do_sys_openat2+0x13f/0x500 fs/open.c:1348 do_sys_open fs/open.c:1364 [inline] __do_sys_open fs/open.c:1372 [inline] __se_sys_open fs/open.c:1368 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1368 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&iint->mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 process_measurement+0x7c0/0x1ce0 security/integrity/ima/ima_main.c:262 ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:539 do_open fs/namei.c:3562 [inline] path_openat+0x280a/0x3170 fs/namei.c:3715 do_filp_open+0x234/0x490 fs/namei.c:3742 do_sys_openat2+0x13f/0x500 fs/open.c:1348 do_sys_open fs/open.c:1364 [inline] __do_sys_open fs/open.c:1372 [inline] __se_sys_open fs/open.c:1368 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1368 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#4); lock(&iint->mutex); lock(sb_writers#4); lock(&iint->mutex); *** DEADLOCK *** 1 lock held by syz-executor.5/8699: #0: ffff88814b7e4460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:394 stack backtrace: CPU: 0 PID: 8699 Comm: syz-executor.5 Not tainted 6.3.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2fe/0x3b0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799 process_measurement+0x7c0/0x1ce0 security/integrity/ima/ima_main.c:262 ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:539 do_open fs/namei.c:3562 [inline] path_openat+0x280a/0x3170 fs/namei.c:3715 do_filp_open+0x234/0x490 fs/namei.c:3742 do_sys_openat2+0x13f/0x500 fs/open.c:1348 do_sys_open fs/open.c:1364 [inline] __do_sys_open fs/open.c:1372 [inline] __se_sys_open fs/open.c:1368 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1368 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa71808c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa718ea9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fa7181abf80 RCX: 00007fa71808c169 RDX: 0000000000000000 RSI: 000000000014d27e RDI: 0000000020000180 RBP: 00007fa7180e7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffce0f050f R14: 00007fa718ea9300 R15: 0000000000022000