@@ -352,7 +352,7 @@ static int mon_text_open(struct inode *inode, struct file *file)
rp->r.rnf_error = mon_text_error;
rp->r.rnf_complete = mon_text_complete;
- snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp);
+ scnprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp);
rp->e_slab = kmem_cache_create(rp->slab_name,
sizeof(struct mon_event_text), sizeof(long), 0,
mon_text_ctor);
@@ -700,46 +700,28 @@ static const struct file_operations mon_fops_text_u = {
int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
{
- enum { NAMESZ = 10 };
+ enum { NAMESZ = 12 };
char name[NAMESZ];
int busnum = ubus? ubus->busnum: 0;
- int rc;
if (mon_dir == NULL)
return 0;
if (ubus != NULL) {
- rc = snprintf(name, NAMESZ, "%dt", busnum);
- if (rc <= 0 || rc >= NAMESZ)
- goto err_print_t;
+ scnprintf(name, NAMESZ, "%dt", busnum);
mbus->dent_t = debugfs_create_file(name, 0600, mon_dir, mbus,
&mon_fops_text_t);
}
- rc = snprintf(name, NAMESZ, "%du", busnum);
- if (rc <= 0 || rc >= NAMESZ)
- goto err_print_u;
+ scnprintf(name, NAMESZ, "%du", busnum);
mbus->dent_u = debugfs_create_file(name, 0600, mon_dir, mbus,
&mon_fops_text_u);
- rc = snprintf(name, NAMESZ, "%ds", busnum);
- if (rc <= 0 || rc >= NAMESZ)
- goto err_print_s;
+ scnprintf(name, NAMESZ, "%ds", busnum);
mbus->dent_s = debugfs_create_file(name, 0600, mon_dir, mbus,
&mon_fops_stat);
return 1;
-
-err_print_s:
- debugfs_remove(mbus->dent_u);
- mbus->dent_u = NULL;
-err_print_u:
- if (ubus != NULL) {
- debugfs_remove(mbus->dent_t);
- mbus->dent_t = NULL;
- }
-err_print_t:
- return 0;
}
void mon_text_del(struct mon_bus *mbus)
There is a general misunderstanding amongst engineers that {v}snprintf() returns the length of the data *actually* encoded into the destination array. However, as per the C99 standard {v}snprintf() really returns the length of the data that *would have been* written if there were enough space for it. This misunderstanding has led to buffer-overruns in the past. It's generally considered safer to use the {v}scnprintf() variants in their place (or even sprintf() in simple cases). So let's do that. Link: https://lwn.net/Articles/69419/ Link: https://github.com/KSPP/linux/issues/105 Signed-off-by: Lee Jones <lee@kernel.org> --- drivers/usb/mon/mon_text.c | 28 +++++----------------------- 1 file changed, 5 insertions(+), 23 deletions(-)