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authorNeil Horman <nhorman@redhat.com>2005-06-23 00:09:11 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-23 09:45:19 -0700
commitac20427ef6aa63da663bdc88b71d16f7394f5e23 (patch)
tree49ba4f88c5cea42d59b386c508174f585efc8a01 /drivers/block
parent3bc1ee3e8f1c05c0f64a479c6d56eb34a6190599 (diff)
downloadlinux-ac20427ef6aa63da663bdc88b71d16f7394f5e23.tar.bz2
[PATCH] add check to /proc/devices read routines
Patch to add check to get_chrdev_list and get_blkdev_list to prevent reads of /proc/devices from spilling over the provided page if more than 4096 bytes of string data are generated from all the registered character and block devices in a system Signed-off-by: Neil Horman <nhorman@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: <viro@parcelfarce.linux.theplanet.co.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/genhd.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c
index 43805e4d31e9..47fd3659a061 100644
--- a/drivers/block/genhd.c
+++ b/drivers/block/genhd.c
@@ -40,7 +40,7 @@ static inline int major_to_index(int major)
#ifdef CONFIG_PROC_FS
/* get block device names in somewhat random order */
-int get_blkdev_list(char *p)
+int get_blkdev_list(char *p, int used)
{
struct blk_major_name *n;
int i, len;
@@ -49,10 +49,18 @@ int get_blkdev_list(char *p)
down(&block_subsys_sem);
for (i = 0; i < ARRAY_SIZE(major_names); i++) {
- for (n = major_names[i]; n; n = n->next)
+ for (n = major_names[i]; n; n = n->next) {
+ /*
+ * If the curent string plus the 5 extra characters
+ * in the line would run us off the page, then we're done
+ */
+ if ((len + used + strlen(n->name) + 5) >= PAGE_SIZE)
+ goto page_full;
len += sprintf(p+len, "%3d %s\n",
n->major, n->name);
+ }
}
+page_full:
up(&block_subsys_sem);
return len;