From 9c9b11ce6df06053deac4095f9b346049cb6031c Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Mon, 28 Jan 2008 23:58:27 -0500
Subject: [PATCH] --- yaml --- r: 77890 b: refs/heads/master c:
 e7c95593001cb96ef5dd121a4523286c574c7133 h: refs/heads/master v: v3

---
 [refs]                |  2 +-
 trunk/fs/ext4/super.c | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 147d95c059ba..8e8236a98bf0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 07620f69eff6671fea6bd382c95709f757e33768
+refs/heads/master: e7c95593001cb96ef5dd121a4523286c574c7133
diff --git a/trunk/fs/ext4/super.c b/trunk/fs/ext4/super.c
index 1484a087bba0..32e3ecb35cd7 100644
--- a/trunk/fs/ext4/super.c
+++ b/trunk/fs/ext4/super.c
@@ -1997,6 +1997,17 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
 		goto cantfind_ext4;
+
+	/* ensure blocks_count calculation below doesn't sign-extend */
+	if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
+	    le32_to_cpu(es->s_first_data_block) + 1) {
+		printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
+		       "first data block %u, blocks per group %lu\n",
+			ext4_blocks_count(es),
+			le32_to_cpu(es->s_first_data_block),
+			EXT4_BLOCKS_PER_GROUP(sb));
+		goto failed_mount;
+	}
 	blocks_count = (ext4_blocks_count(es) -
 			le32_to_cpu(es->s_first_data_block) +
 			EXT4_BLOCKS_PER_GROUP(sb) - 1);