Re: [syzbot] Re: [syzbot] [ntfs3?] general protection fault in pick_link

[syzbot <syzbot+73d8fc29ec7cba8286fa@syzkaller.appspotmail.com>]

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***

Subject: Re: [syzbot] [ntfs3?] general protection fault in pick_link
Author: lizhi.xu@windriver.com

the symlink inode is corrupted.

#syz test

diff --git a/fs/namei.c b/fs/namei.c
index 4a4a22a08ac2..f5dbccb3aafc 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1844,6 +1844,9 @@ static const char *pick_link(struct nameidata *nd, struct path *link,
 	if (unlikely(error))
 		return ERR_PTR(error);
 
+	if (!S_ISLNK(inode->i_mode))
+		return ERR_PTR(-EINVAL);
+
 	res = READ_ONCE(inode->i_link);
 	if (!res) {
 		const char * (*get)(struct dentry *, struct inode *,