[syzbot] WARNING in ext4_xattr_block_set

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b229b6ca5abb Merge tag 'perf-tools-fixes-for-v6.1-2022-10-..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=120f2c0e880000
kernel config: https://syzkaller.appspot.com/x/.config?x=1d3548a4365ba17d
dashboard link: https://syzkaller.appspot.com/bug?extid=98346927678ac3059c77
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=168cc339880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=119ac77a880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/24728b72a896/disk-b229b6ca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/10a3c40c60e1/vmlinux-b229b6ca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/69f963b02b7e/bzImage-b229b6ca.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4dd9a1b9ecac/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+983469...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
EXT4-fs: Journaled quota options ignored when QUOTA feature is enabled
EXT4-fs (loop0): mounted filesystem without journal. Quota mode: writeback.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 3611 at fs/ext4/xattr.c:2069 ext4_xattr_block_set+0x315f/0x3920
Modules linked in:
CPU: 0 PID: 3611 Comm: syz-executor383 Not tainted 6.1.0-rc2-syzkaller-00105-gb229b6ca5abb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:ext4_xattr_block_set+0x315f/0x3920 fs/ext4/xattr.c:2069
Code: f0 41 ff 48 8b 7c 24 58 4c 89 fe e8 fb 64 c2 ff 45 31 e4 e9 24 f5 ff ff e8 7e f0 41 ff 45 31 e4 e9 17 f5 ff ff e8 71 f0 41 ff <0f> 0b e9 4e f2 ff ff e8 65 f0 41 ff 0f 0b e9 22 df ff ff 44 89 f9
RSP: 0018:ffffc90003e6f0a0 EFLAGS: 00010293
RAX: ffffffff8245df6f RBX: ffffc90003e6f1e8 RCX: ffff888023aa8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc90003e6f2f0 R08: ffffffff820bd909 R09: ffffed1005342b23
R10: ffffed1005342b23 R11: 1ffff11005342b22 R12: ffff888075fcd2f0
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff11004ba8405
FS: 0000555556b01300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559471603278 CR3: 000000007bbfe000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ext4_xattr_move_to_block fs/ext4/xattr.c:2604 [inline]
ext4_xattr_make_inode_space fs/ext4/xattr.c:2673 [inline]
ext4_expand_extra_isize_ea+0x137b/0x1cd0 fs/ext4/xattr.c:2765
__ext4_expand_extra_isize+0x2b8/0x3f0 fs/ext4/inode.c:5857
ext4_try_to_expand_extra_isize fs/ext4/inode.c:5900 [inline]
__ext4_mark_inode_dirty+0x51a/0x670 fs/ext4/inode.c:5978
ext4_rename fs/ext4/namei.c:3907 [inline]
ext4_rename2+0x2936/0x4760 fs/ext4/namei.c:4169
vfs_rename+0xd53/0x1130 fs/namei.c:4778
do_renameat2+0xb53/0x1370 fs/namei.c:4929
__do_sys_rename fs/namei.c:4975 [inline]
__se_sys_rename fs/namei.c:4973 [inline]
__x64_sys_rename+0x82/0x90 fs/namei.c:4973
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: 0033:0x7f400cc61b29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe83d770a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f400cc61b29
RDX: 00007f400cc20023 RSI: 00000000200000c0 RDI: 0000000020000080
RBP: 00007f400cc212f0 R08: 00007ffe83d76fa0 R09: 0000000000000000
R10: 00007ffe83d76f70 R11: 0000000000000246 R12: 00007f400cc21380
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>


---
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[Theodore Ts'o]

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 39f00f05f981..dab33412b858 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6638,6 +6638,14 @@ static int __ext4_remount(struct fs_context *fc, struct super_block *sb)
return 0;

restore_opts:
+ if ((sb->s_flags & SB_RDONLY) &&
+ !(old_sb_flags & SB_RDONLY)) {
+ ext4_warning(sb, "failing rw->ro transition");
+ if (sb_any_quota_suspended(sb)) {
+ ext4_warning(sb, "would resume quotas");
+// dquot_resume(sb, -1);
+ }
+ }
sb->s_flags = old_sb_flags;
sbi->s_mount_opt = old_opts.s_mount_opt;
sbi->s_mount_opt2 = old_opts.s_mount_opt2;

[syzbot]

> #syz test git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev

This bug is already marked as fixed. No point in testing.