[PATCH] clean up missing overflow check in get_blkdev_list

[PATCH] clean up missing overflow check in get_blkdev_list

[Neil Horman]

Patch to clean up missing overflow check in get_blkdev_list.  the printf which
adds the "Block Devices" string in /proc/devices can overflow the presented page
if get_chrdev_list eats up the entire 4k space. Tested by myself, with good
results.

Signed-off-by: Neil Horman <nhorman@redhat.com>

 genhd.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)



--- linux-2.6/drivers/block/genhd.c.orig	2005-08-16 10:12:02.000000000 -0400
+++ linux-2.6/drivers/block/genhd.c	2005-08-16 10:12:27.000000000 -0400
@@ -45,7 +45,7 @@ int get_blkdev_list(char *p, int used)
 	struct blk_major_name *n;
 	int i, len;
 
-	len = sprintf(p, "\nBlock devices:\n");
+	len = snprintf(p, (PAGE_SIZE-used), "\nBlock devices:\n");
 
 	down(&block_subsys_sem);
 	for (i = 0; i < ARRAY_SIZE(major_names); i++) {
-- 
/***************************************************
 *Neil Horman
 *Software Engineer
 *Red Hat, Inc.
 *nhorman@redhat.com
 *gpg keyid: 1024D / 0x92A74FA1
 *http://pgp.mit.edu
 ***************************************************/

Re: [PATCH] clean up missing overflow check in get_blkdev_list

[Christoph Hellwig]

On Tue, Aug 16, 2005 at 02:48:13PM -0400, Neil Horman wrote:
> Patch to clean up missing overflow check in get_blkdev_list.  the printf which
> adds the "Block Devices" string in /proc/devices can overflow the presented page
> if get_chrdev_list eats up the entire 4k space. Tested by myself, with good
> results.

Please switch /proc/device over to the proper seq_file model instead.