From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 22 Apr 2013 02:56:32 +0000 (-0400)
Subject: ext4: add check for inodes_count overflow in new resize ioctl
X-Git-Tag: v3.4.45~18
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5d96a5f6c32bc97f2f2ff8e614de09ce6e2431c0;p=linux

ext4: add check for inodes_count overflow in new resize ioctl

commit 3f8a6411fbada1fa482276591e037f3b1adcf55b upstream.

Addresses-Red-Hat-Bugzilla: #913245

Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Lingzhu Xiang <lxiang@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index 9202b22383c1..86a8c88dc29a 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -1630,6 +1630,10 @@ int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
 		return 0;
 
 	ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
+	if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) {
+		ext4_warning(sb, "resize would cause inodes_count overflow");
+		return -EINVAL;
+	}
 	ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
 
 	n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) /