cfg80211: regulatory: reject invalid hints

commit 47caf685a6854593348f216e0b489b71c10cbe03 upstream.

Reject invalid hints early in order to not cause a kernel
WARN later if they're restored to or similar.

Reported-by: syzbot+d451401ffd00a60677ee@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=d451401ffd00a60677ee
Link: https://lore.kernel.org/r/20200819084648.13956-1-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 1a8218f1bbe075457441e39da8e14220e375701d..20a8e6af88c457c650de79861fe13f9eb41bcdf6 100644 (file)
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -2941,6 +2941,9 @@ int regulatory_hint_user(const char *alpha2,
        if (WARN_ON(!alpha2))
                return -EINVAL;
 
+       if (!is_world_regdom(alpha2) && !is_an_alpha2(alpha2))
+               return -EINVAL;
+
        request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
        if (!request)
                return -ENOMEM;