Hello, syzbot found the following issue on: HEAD commit: 0d3eb744aed4 Merge tag 'urgent-rcu.2023.04.07a' of git://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11798e4bc80000 kernel config: https://syzkaller.appspot.com/x/.config?x=c21559e740385326 dashboard link: https://syzkaller.appspot.com/bug?extid=cdcd444e4d3a256ada13 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a02928003efa/disk-0d3eb744.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/7839447005a4/vmlinux-0d3eb744.xz kernel image: https://storage.googleapis.com/syzbot-assets/d26ab3184148/bzImage-0d3eb744.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+cdcd444e4d3a256ada13@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.3.0-rc6-syzkaller-00016-g0d3eb744aed4 #0 Not tainted ------------------------------------------------------ syz-executor.3/11858 is trying to acquire lock: ffff88802a3bc0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __do_sys_quotactl_fd+0x174/0x3f0 fs/quota/quota.c:997 but task is already holding lock: ffff88802a3bc460 (sb_writers#4){.+.+}-{0:0}, at: __do_sys_quotactl_fd+0xd3/0x3f0 fs/quota/quota.c:990 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sb_writers#4){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1477 [inline] sb_start_write include/linux/fs.h:1552 [inline] write_mmp_block+0xc4/0x820 fs/ext4/mmp.c:50 ext4_multi_mount_protect+0x50d/0xac0 fs/ext4/mmp.c:343 __ext4_remount fs/ext4/super.c:6543 [inline] ext4_reconfigure+0x242b/0x2b60 fs/ext4/super.c:6642 reconfigure_super+0x40c/0xa30 fs/super.c:956 vfs_fsconfig_locked fs/fsopen.c:254 [inline] __do_sys_fsconfig+0xa3a/0xc20 fs/fsopen.c:439 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 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 kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 down_write+0x92/0x200 kernel/locking/rwsem.c:1573 __do_sys_quotactl_fd+0x174/0x3f0 fs/quota/quota.c:997 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 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.3/11858: #0: ffff88802a3bc460 (sb_writers#4){.+.+}-{0:0}, at: __do_sys_quotactl_fd+0xd3/0x3f0 fs/quota/quota.c:990 stack backtrace: CPU: 0 PID: 11858 Comm: syz-executor.3 Not tainted 6.3.0-rc6-syzkaller-00016-g0d3eb744aed4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 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 kernel/locking/lockdep.c:3832 [inline] __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 down_write+0x92/0x200 kernel/locking/rwsem.c:1573 __do_sys_quotactl_fd+0x174/0x3f0 fs/quota/quota.c:997 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f81d2e8c169 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:00007f81d3b29168 EFLAGS: 00000246 ORIG_RAX: 00000000000001bb RAX: ffffffffffffffda RBX: 00007f81d2fabf80 RCX: 00007f81d2e8c169 RDX: 0000000000000000 RSI: ffffffff80000300 RDI: 0000000000000003 RBP: 00007f81d2ee7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffeeb18d7f R14: 00007f81d3b29300 R15: 0000000000022000 </TASK> --- This report is generated by a bot. 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