diff options
| author | Neil Horman <nhorman@redhat.com> | 2005-06-23 00:09:11 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-23 09:45:19 -0700 |
| commit | ac20427ef6aa63da663bdc88b71d16f7394f5e23 (patch) | |
| tree | 49ba4f88c5cea42d59b386c508174f585efc8a01 | |
| parent | 3bc1ee3e8f1c05c0f64a479c6d56eb34a6190599 (diff) | |
[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>
| -rw-r--r-- | drivers/block/genhd.c | 12 | ||||
| -rw-r--r-- | fs/char_dev.c | 13 | ||||
| -rw-r--r-- | fs/proc/proc_misc.c | 2 | ||||
| -rw-r--r-- | include/linux/genhd.h | 2 |
4 files changed, 24 insertions, 5 deletions
diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c index 43805e4d31e..47fd3659a06 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; diff --git a/fs/char_dev.c b/fs/char_dev.c index c1e3537909f..e82aac9cc2f 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -56,10 +56,21 @@ int get_chrdev_list(char *page) down(&chrdevs_lock); for (i = 0; i < ARRAY_SIZE(chrdevs) ; i++) { - for (cd = chrdevs[i]; cd; cd = cd->next) + for (cd = chrdevs[i]; cd; cd = cd->next) { + /* + * if the current name, plus the 5 extra characters + * in the device line for this entry + * would run us off the page, we're done + */ + if ((len+strlen(cd->name) + 5) >= PAGE_SIZE) + goto page_full; + + len += sprintf(page+len, "%3d %s\n", cd->major, cd->name); + } } +page_full: up(&chrdevs_lock); return len; diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c index 63a9fbf1ac5..94b570ad037 100644 --- a/fs/proc/proc_misc.c +++ b/fs/proc/proc_misc.c @@ -451,7 +451,7 @@ static int devices_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { int len = get_chrdev_list(page); - len += get_blkdev_list(page+len); + len += get_blkdev_list(page+len, len); return proc_calc_metrics(page, start, off, count, eof, len); } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index af26dc718ef..01796c41c95 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -224,7 +224,7 @@ static inline void free_disk_stats(struct gendisk *disk) extern void disk_round_stats(struct gendisk *disk); /* drivers/block/genhd.c */ -extern int get_blkdev_list(char *); +extern int get_blkdev_list(char *, int); extern void add_disk(struct gendisk *disk); extern void del_gendisk(struct gendisk *gp); extern void unlink_gendisk(struct gendisk *gp); |