| Message ID | 20171112231511.4666-2-linux@rasmusvillemoes.dk |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: core: devname allocation cleanups | expand |
diff --git a/net/core/dev.c b/net/core/dev.c index 11596a302a26..87e19804757b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1062,7 +1062,7 @@ static int __dev_alloc_name(struct net *net, const char *name, char *buf) unsigned long *inuse; struct net_device *d; - p = strnchr(name, IFNAMSIZ-1, '%'); + p = strchr(name, '%'); if (p) { /* * Verify the string as this thing may have come from
__dev_alloc_name is called from the public (and exported) dev_alloc_name(), so we don't have a guarantee that strlen(name) is at most IFNAMSIZ. If somebody manages to get __dev_alloc_name called with a % char beyond the 31st character, we'd be making a snprintf() call that will very easily crash the kernel (using an appropriate %p extension, we'll likely dereference some completely bogus pointer). In the normal case where strlen() is sane, we don't even save anything by limiting to IFNAMSIZ, so just use strchr(). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)