From: Theodore Ts'o <tytso@mit.edu>
Date: Sun, 29 Dec 2013 03:25:11 +0000 (-0500)
Subject: e2freefrag: avoid integer overflow when reporting free space statistics
X-Git-Tag: v1.42.9~10
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=d05508956734d55f7ee286085a1f6570d11848b7;p=tools%2Fe2fsprogs.git

e2freefrag: avoid integer overflow when reporting free space statistics

An integer overflow could happen if the file system is large and has
very large contiguous chunks of free space.

Addresses-Debian-Bug: #718205

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/misc/e2freefrag.c b/misc/e2freefrag.c
index 58f1ff5..612ca44 100644
--- a/misc/e2freefrag.c
+++ b/misc/e2freefrag.c
@@ -172,10 +172,10 @@ static errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info,
 
 	/* Display chunk information in KB */
 	if (info->real_free_chunks) {
-		info->min = (info->min * fs->blocksize) >> 10;
-		info->max = (info->max * fs->blocksize) >> 10;
-		info->avg = (info->avg / info->real_free_chunks *
-			     fs->blocksize) >> 10;
+		unsigned int scale = fs->blocksize >> 10;
+		info->min = info->min * scale;
+		info->max = info->max * scale;
+		info->avg = info->avg / info->real_free_chunks * scale;
 	} else {
 		info->min = 0;
 	}