From: Jan Kara <jack@suse.cz>
Date: Fri, 25 Sep 2020 12:53:08 +0000 (+0200)
Subject: udf: Limit sparing table size
X-Git-Tag: v5.4.73~51
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=01d886b89eb831d3366994064ddb805e66416c61;p=users%2Fdwmw2%2Flinux.git

udf: Limit sparing table size

[ Upstream commit 44ac6b829c4e173fdf6df18e6dd86aecf9a3dc99 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 4baa1ca91e9be..a0cd766b41cdb 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1352,6 +1352,12 @@ 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]);