From: Jan Kara <jack@suse.cz>
Date: Fri, 25 Sep 2020 12:53:08 +0000 (+0200)
Subject: udf: Limit sparing table size
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=44ac6b829c4e173fdf6df18e6dd86aecf9a3dc99;p=linux.git

udf: Limit sparing table size

Although UDF standard allows it, we don't support sparing table larger
than a single block. Check it during mount so that we don't try to
access memory beyond end of buffer.

Reported-by: syzbot+9991561e714f597095da@syzkaller.appspotmail.com
Signed-off-by: Jan Kara <jack@suse.cz>
---

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 413a50599d1c4..faf2017ada111 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1345,6 +1345,12 @@ static int udf_load_sparable_map(struct super_block *sb,
 			(int)spm->numSparingTables);
 		return -EIO;
 	}
+	if (le32_to_cpu(spm->sizeSparingTable) > sb->s_blocksize) {
+		udf_err(sb, "error loading logical volume descriptor: "
+			"Too big sparing table size (%u)\n",
+			le32_to_cpu(spm->sizeSparingTable));
+		return -EIO;
+	}
 
 	for (i = 0; i < spm->numSparingTables; i++) {
 		loc = le32_to_cpu(spm->locSparingTable[i]);