====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-00068-g49c13ed0316d #0 Not tainted ------------------------------------------------------ syz-executor213/30937 is trying to acquire lock: ffff88801d6c7f20 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7ab/0x1bd0 security/integrity/ima/ima_main.c:260 but task is already holding lock: ffff888028594460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sb_writers#4){.+.+}-{0:0}: lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_write+0x4d/0x1a0 include/linux/fs.h:1901 mnt_want_write+0x3b/0x80 fs/namespace.c:393 ovl_maybe_copy_up+0x124/0x190 fs/overlayfs/copy_up.c:1077 ovl_open+0xf3/0x290 fs/overlayfs/file.c:152 do_dentry_open+0x777/0x1180 fs/open.c:880 vfs_open fs/open.c:1016 [inline] dentry_open+0xc1/0x120 fs/open.c:1032 ima_calc_file_hash+0x15b/0x1ca0 security/integrity/ima/ima_crypto.c:558 ima_collect_measurement+0x39b/0x800 security/integrity/ima/ima_api.c:292 process_measurement+0xf4b/0x1bd0 security/integrity/ima/ima_main.c:337 ima_file_check+0xd8/0x130 security/integrity/ima/ima_main.c:517 do_open fs/namei.c:3559 [inline] path_openat+0x2642/0x2df0 fs/namei.c:3691 do_filp_open+0x264/0x4f0 fs/namei.c:3718 do_sys_openat2+0x124/0x4e0 fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1340 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 (&iint->mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain+0x1873/0x6c00 kernel/locking/lockdep.c:3829 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666 __mutex_lock_common+0x1bd/0x26e0 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+0x7ab/0x1bd0 security/integrity/ima/ima_main.c:260 ima_file_check+0xd8/0x130 security/integrity/ima/ima_main.c:517 do_open fs/namei.c:3559 [inline] path_openat+0x2642/0x2df0 fs/namei.c:3691 do_filp_open+0x264/0x4f0 fs/namei.c:3718 do_sys_openat2+0x124/0x4e0 fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_open fs/open.c:1337 [inline] __se_sys_open fs/open.c:1333 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1333 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(sb_writers#4); lock(&iint->mutex); lock(sb_writers#4); lock(&iint->mutex); *** DEADLOCK *** 1 lock held by syz-executor213/30937: #0: ffff888028594460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393 stack backtrace: CPU: 1 PID: 30937 Comm: syz-executor213 Not tainted 6.0.0-rc7-syzkaller-00068-g49c13ed0316d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain+0x1873/0x6c00 kernel/locking/lockdep.c:3829 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5053 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5666 __mutex_lock_common+0x1bd/0x26e0 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+0x7ab/0x1bd0 security/integrity/ima/ima_main.c:260 ima_file_check+0xd8/0x130 security/integrity/ima/ima_main.c:517 do_open fs/namei.c:3559 [inline] path_openat+0x2642/0x2df0 fs/namei.c:3691 do_filp_open+0x264/0x4f0 fs/namei.c:3718 do_sys_openat2+0x124/0x4e0 fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_open fs/open.c:1337 [inline] __se_sys_open fs/open.c:1333 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1333 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: 0033:0x7f64320890c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 18 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:00007f643202e208 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f643210b488 RCX: 00007f64320890c9 RDX: 0000000000000000 RSI: 0000000000080202 RDI: 0000000020000000 RBP: 00007f643210b480 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f643210b48c R13: 00007ffe47a7edbf R14: 00007f643202e300 R15: 0000000000022000