Re: [syzbot] Re: [syzbot] [overlayfs?] WARNING in ovl_listxattr

[syzbot <syzbot+4125590f2a9f5b3cdf43@syzkaller.appspotmail.com>]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: Re: [syzbot] [overlayfs?] WARNING in ovl_listxattr
Author: lizhi.xu@windriver.com

#syz test

diff --git a/fs/overlayfs/xattrs.c b/fs/overlayfs/xattrs.c
index 88055deca936..69e17db853f5 100644
--- a/fs/overlayfs/xattrs.c
+++ b/fs/overlayfs/xattrs.c
@@ -122,6 +122,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 	old_cred = ovl_override_creds(dentry->d_sb);
 	res = vfs_listxattr(realdentry, list, size);
 	ovl_revert_creds(old_cred);
+	printk("buf: %s, size: %lu, res: %ld, %s\n", list, size, res, __func__);
 	if (res <= 0 || size == 0)
 		return res;
 
@@ -131,6 +132,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
 	/* filter out private xattrs */
 	for (s = list, len = res; len;) {
 		size_t slen = strnlen(s, len) + 1;
+		printk("s: %s, len: %lu, slen: %lu, %s\n", s, len, slen, __func__);
 
 		/* underlying fs providing us with an broken xattr list? */
 		if (WARN_ON(slen > len))