======================================================
WARNING: possible circular locking dependency detected
6.1.27-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/9544 is trying to acquire lock:
ffff88807f7ae0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __do_sys_quotactl_fd fs/quota/quota.c:999 [inline]
ffff88807f7ae0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __se_sys_quotactl_fd+0x24a/0x3b0 fs/quota/quota.c:972
but task is already holding lock:
ffff88807f7ae460 (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+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1832 [inline]
sb_start_write include/linux/fs.h:1907 [inline]
write_mmp_block+0xe1/0x930 fs/ext4/mmp.c:50
ext4_multi_mount_protect+0x54a/0x990 fs/ext4/mmp.c:349
__ext4_remount fs/ext4/super.c:6530 [inline]
ext4_reconfigure+0x2d30/0x3610 fs/ext4/super.c:6629
reconfigure_super+0x3c5/0x7c0 fs/super.c:957
vfs_fsconfig_locked fs/fsopen.c:254 [inline]
__do_sys_fsconfig fs/fsopen.c:439 [inline]
__se_sys_fsconfig+0x98b/0xec0 fs/fsopen.c:314
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 (&type->s_umount_key#31){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
__do_sys_quotactl_fd fs/quota/quota.c:999 [inline]
__se_sys_quotactl_fd+0x24a/0x3b0 fs/quota/quota.c:972
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(&type->s_umount_key#31);
lock(sb_writers#4);
lock(&type->s_umount_key#31);
*** DEADLOCK ***
1 lock held by syz-executor.4/9544:
#0: ffff88807f7ae460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
stack backtrace:
CPU: 1 PID: 9544 Comm: syz-executor.4 Not tainted 6.1.27-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call Trace:
<TASK>
__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:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
down_read+0x39/0x50 kernel/locking/rwsem.c:1520
__do_sys_quotactl_fd fs/quota/quota.c:999 [inline]
__se_sys_quotactl_fd+0x24a/0x3b0 fs/quota/quota.c:972
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: 0033:0x7f592ec8c169
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:00007f592f9ba168 EFLAGS: 00000246 ORIG_RAX: 00000000000001bb
RAX: ffffffffffffffda RBX: 00007f592edabf80 RCX: 00007f592ec8c169
RDX: ffffffffffffffff RSI: ffffffff80000602 RDI: 0000000000000003
RBP: 00007f592ece7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff167a250f R14: 00007f592f9ba300 R15: 0000000000022000
</TASK>