linux-kernel - [PATCH] VFS: check i_nlink count before trying to unlink

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Message-Id: <20240907172111.127817-1-ghanshyam1898@gmail.com>
Date: Sat,  7 Sep 2024 22:51:10 +0530
From: Ghanshyam Agrawal <ghanshyam1898@...il.com>
To: viro@...iv.linux.org.uk,
	brauner@...nel.org,
	jack@...e.cz
Cc: Ghanshyam Agrawal <ghanshyam1898@...il.com>,
	linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	syzbot+41b43444de86db4c5ed1@...kaller.appspotmail.com
Subject: [PATCH] VFS: check i_nlink count before trying to unlink

Reported-by: syzbot+41b43444de86db4c5ed1@...kaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=41b43444de86db4c5ed1
Signed-off-by: Ghanshyam Agrawal <ghanshyam1898@...il.com>
---
 fs/namei.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/namei.c b/fs/namei.c
index 5512cb10fa89..9e5214dfd05d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4419,7 +4419,8 @@ int vfs_unlink(struct mnt_idmap *idmap, struct inode *dir,
 			error = try_break_deleg(target, delegated_inode);
 			if (error)
 				goto out;
-			error = dir->i_op->unlink(dir, dentry);
+			if (dentry->d_inode->i_nlink)
+				error = dir->i_op->unlink(dir, dentry);
 			if (!error) {
 				dont_mount(dentry);
 				detach_mounts(dentry);
-- 
2.34.1