====================================================== WARNING: possible circular locking dependency detected 6.1.51-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/10432 is trying to acquire lock: ffff88814b3a4460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393 but task is already holding lock: ffff8880152c8f20 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7fe/0x1cf0 security/integrity/ima/ima_main.c:260 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&iint->mutex){+.+.}-{3:3}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 process_measurement+0x7fe/0x1cf0 security/integrity/ima/ima_main.c:260 ima_file_check+0xed/0x170 security/integrity/ima/ima_main.c:520 do_open fs/namei.c:3559 [inline] path_openat+0x2687/0x2e60 fs/namei.c:3714 do_filp_open+0x230/0x480 fs/namei.c:3741 do_sys_openat2+0x13b/0x500 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_open fs/open.c:1342 [inline] __se_sys_open fs/open.c:1338 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1338 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sb_writers#4){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3824 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5048 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1832 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1907 mnt_want_write+0x3b/0x80 fs/namespace.c:393 ovl_maybe_copy_up+0x111/0x180 fs/overlayfs/copy_up.c:1089 ovl_open+0x108/0x2a0 fs/overlayfs/file.c:153 do_dentry_open+0x7f9/0x10f0 fs/open.c:882 vfs_open fs/open.c:1013 [inline] dentry_open+0xc1/0x120 fs/open.c:1029 ima_calc_file_hash+0x159/0x1c00 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x4d4/0x970 security/integrity/ima/ima_api.c:292 process_measurement+0x1018/0x1cf0 security/integrity/ima/ima_main.c:337 ima_file_check+0xed/0x170 security/integrity/ima/ima_main.c:520 do_open fs/namei.c:3559 [inline] path_openat+0x2687/0x2e60 fs/namei.c:3714 do_filp_open+0x230/0x480 fs/namei.c:3741 do_sys_openat2+0x13b/0x500 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_open fs/open.c:1342 [inline] __se_sys_open fs/open.c:1338 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1338 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 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(&iint->mutex); lock(sb_writers#4); lock(&iint->mutex); lock(sb_writers#4); *** DEADLOCK *** 1 lock held by syz-executor.4/10432: #0: ffff8880152c8f20 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7fe/0x1cf0 security/integrity/ima/ima_main.c:260 stack backtrace: CPU: 0 PID: 10432 Comm: syz-executor.4 Not tainted 6.1.51-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3824 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5048 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1832 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1907 mnt_want_write+0x3b/0x80 fs/namespace.c:393 ovl_maybe_copy_up+0x111/0x180 fs/overlayfs/copy_up.c:1089 ovl_open+0x108/0x2a0 fs/overlayfs/file.c:153 do_dentry_open+0x7f9/0x10f0 fs/open.c:882 vfs_open fs/open.c:1013 [inline] dentry_open+0xc1/0x120 fs/open.c:1029 ima_calc_file_hash+0x159/0x1c00 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x4d4/0x970 security/integrity/ima/ima_api.c:292 process_measurement+0x1018/0x1cf0 security/integrity/ima/ima_main.c:337 ima_file_check+0xed/0x170 security/integrity/ima/ima_main.c:520 do_open fs/namei.c:3559 [inline] path_openat+0x2687/0x2e60 fs/namei.c:3714 do_filp_open+0x230/0x480 fs/namei.c:3741 do_sys_openat2+0x13b/0x500 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_open fs/open.c:1342 [inline] __se_sys_open fs/open.c:1338 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1338 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb64887cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb6495300c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fb64899bf80 RCX: 00007fb64887cae9 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 00000000200000c0 RBP: 00007fb6488c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fb64899bf80 R15: 00007ffd7b58c148