From: Eric Sandeen <sandeen@redhat.com>
Date: Wed, 16 Jan 2008 21:36:44 +0000 (+0200)
Subject: limit minixfs printks on corrupted dir i_size (CVE-2006-6058)
X-Git-Tag: v2.6.16.59-rc1~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=51828e03b3b5627ef6a102f75c565bec85cab040;p=thirdparty%2Fkernel%2Fstable.git

limit minixfs printks on corrupted dir i_size (CVE-2006-6058)

First reported at http://projects.info-pull.com/mokb/MOKB-17-11-2006.html

Essentially a corrupted minix dir inode reporting a very large
i_size will loop for a very long time in minix_readdir, minix_find_entry,
etc, because on EIO they just move on to try the next page.  This is
under the BKL, printk-storming as well.  This can lock up the machine
for a very long time.  Simply ratelimiting the printks gets things back
under control.  Make the message a bit more informative while we're here.

Adrian Bunk:
Backported to 2.6.16.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
---

diff --git a/fs/minix/itree_v1.c b/fs/minix/itree_v1.c
index 656b1347a25be..2f167044d6c02 100644
--- a/fs/minix/itree_v1.c
+++ b/fs/minix/itree_v1.c
@@ -23,11 +23,16 @@ static inline block_t *i_data(struct inode *inode)
 static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
 {
 	int n = 0;
+	char b[BDEVNAME_SIZE];
 
 	if (block < 0) {
-		printk("minix_bmap: block<0\n");
+		printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n",
+			block, bdevname(inode->i_sb->s_bdev, b));
 	} else if (block >= (minix_sb(inode->i_sb)->s_max_size/BLOCK_SIZE)) {
-		printk("minix_bmap: block>big\n");
+		if (printk_ratelimit())
+			printk("MINIX-fs: block_to_path: "
+			       "block %ld too big on dev %s\n",
+				block, bdevname(inode->i_sb->s_bdev, b));
 	} else if (block < 7) {
 		offsets[n++] = block;
 	} else if ((block -= 7) < 512) {
diff --git a/fs/minix/itree_v2.c b/fs/minix/itree_v2.c
index 9adcdc754e0fc..65f74d4db9314 100644
--- a/fs/minix/itree_v2.c
+++ b/fs/minix/itree_v2.c
@@ -23,11 +23,16 @@ static inline block_t *i_data(struct inode *inode)
 static int block_to_path(struct inode * inode, long block, int offsets[DEPTH])
 {
 	int n = 0;
+	char b[BDEVNAME_SIZE];
 
 	if (block < 0) {
-		printk("minix_bmap: block<0\n");
+		printk("MINIX-fs: block_to_path: block %ld < 0 on dev %s\n",
+			block, bdevname(inode->i_sb->s_bdev, b));
 	} else if (block >= (minix_sb(inode->i_sb)->s_max_size/BLOCK_SIZE)) {
-		printk("minix_bmap: block>big\n");
+		if (printk_ratelimit())
+			printk("MINIX-fs: block_to_path: "
+			       "block %ld too big on dev %s\n",
+				block, bdevname(inode->i_sb->s_bdev, b));
 	} else if (block < 7) {
 		offsets[n++] = block;
 	} else if ((block -= 7) < 256) {