====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc6-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/3431 is trying to acquire lock: ffff888105e46460 (sb_writers#4){.+.+}-{0:0}, at: ovl_maybe_copy_up+0x77/0xa0 fs/overlayfs/copy_up.c:996 but task is already holding lock: ffff888106c386d8 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x273/0x880 security/integrity/ima/ima_main.c:253 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&iint->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:949 [inline] __mutex_lock+0x72/0x660 kernel/locking/mutex.c:1096 process_measurement+0x273/0x880 security/integrity/ima/ima_main.c:253 ima_file_check+0x5f/0x80 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3367 [inline] path_openat+0x603/0xaf0 fs/namei.c:3498 do_filp_open+0x83/0x130 fs/namei.c:3525 do_sys_openat2+0x92/0x150 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_openat fs/open.c:1219 [inline] __se_sys_openat fs/open.c:1214 [inline] __x64_sys_openat+0x4f/0x90 fs/open.c:1214 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (sb_writers#4){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:2936 [inline] check_prevs_add kernel/locking/lockdep.c:3059 [inline] validate_chain kernel/locking/lockdep.c:3674 [inline] __lock_acquire+0x110e/0x1b00 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0xc7/0x380 kernel/locking/lockdep.c:5475 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1640 [inline] sb_start_write include/linux/fs.h:1710 [inline] mnt_want_write+0x32/0x1a0 fs/namespace.c:375 ovl_maybe_copy_up+0x77/0xa0 fs/overlayfs/copy_up.c:996 ovl_open+0x25/0x80 fs/overlayfs/file.c:149 do_dentry_open+0x15c/0x3b0 fs/open.c:826 vfs_open fs/open.c:940 [inline] dentry_open+0x5d/0xa0 fs/open.c:956 ima_calc_file_hash+0xf9/0x160 security/integrity/ima/ima_crypto.c:557 ima_collect_measurement+0x205/0x230 security/integrity/ima/ima_api.c:252 process_measurement+0x3bd/0x880 security/integrity/ima/ima_main.c:330 ima_file_check+0x5f/0x80 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3367 [inline] path_openat+0x603/0xaf0 fs/namei.c:3498 do_filp_open+0x83/0x130 fs/namei.c:3525 do_sys_openat2+0x92/0x150 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x50/0x90 fs/open.c:1207 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae 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.0/3431: #0: ffff888106c386d8 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x273/0x880 security/integrity/ima/ima_main.c:253 stack backtrace: CPU: 0 PID: 3431 Comm: syz-executor.0 Not tainted 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x7f/0xad lib/dump_stack.c:120 check_noncircular+0xcc/0xe0 kernel/locking/lockdep.c:2127 check_prev_add kernel/locking/lockdep.c:2936 [inline] check_prevs_add kernel/locking/lockdep.c:3059 [inline] validate_chain kernel/locking/lockdep.c:3674 [inline] __lock_acquire+0x110e/0x1b00 kernel/locking/lockdep.c:4900 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0xc7/0x380 kernel/locking/lockdep.c:5475 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1640 [inline] sb_start_write include/linux/fs.h:1710 [inline] mnt_want_write+0x32/0x1a0 fs/namespace.c:375 ovl_maybe_copy_up+0x77/0xa0 fs/overlayfs/copy_up.c:996 ovl_open+0x25/0x80 fs/overlayfs/file.c:149 do_dentry_open+0x15c/0x3b0 fs/open.c:826 vfs_open fs/open.c:940 [inline] dentry_open+0x5d/0xa0 fs/open.c:956 ima_calc_file_hash+0xf9/0x160 security/integrity/ima/ima_crypto.c:557 ima_collect_measurement+0x205/0x230 security/integrity/ima/ima_api.c:252 process_measurement+0x3bd/0x880 security/integrity/ima/ima_main.c:330 ima_file_check+0x5f/0x80 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3367 [inline] path_openat+0x603/0xaf0 fs/namei.c:3498 do_filp_open+0x83/0x130 fs/namei.c:3525 do_sys_openat2+0x92/0x150 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x50/0x90 fs/open.c:1207 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa05ba91ae9 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:00007fa05b6140c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fa05bbb0f80 RCX: 00007fa05ba91ae9 RDX: 0000000000000000 RSI: 0000000000101003 RDI: 0000000020000000 RBP: 00007fa05badd47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000006 R14: 00007fa05bbb0f80 R15: 00007ffce33ecf48