[PATCH AUTOSEL 4.19 09/26] cfg80211: regulatory: reject invalid hints

[Sasha Levin]

From: Johannes Berg <johannes.berg@xxxxxxxxx>

[ Upstream commit 47caf685a6854593348f216e0b489b71c10cbe03 ]

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

Reported-by: syzbot+d451401ffd00a60677ee@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?extid=d451401ffd00a60677ee
Link: https://lore.kernel.org/r/20200819084648.13956-1-johannes@xxxxxxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/wireless/reg.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 32f575857e415..935aebf150107 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -2936,6 +2936,9 @@ 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;
-- 
2.25.1