[PATCH] wlantest: avoid heap-overflow on unexpected data

[Brian Norris]

We're doing a sort of bounds check, based on the previous loop, but only
after we've already tried to read off the end.

This squashes some ASAN errors I'm seeing when running the ap_ft hwsim
test module.

Signed-off-by: Brian Norris <briannorris at chromium.org>
---
 wlantest/rx_eapol.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/wlantest/rx_eapol.c b/wlantest/rx_eapol.c
index d75ed92ba73d..44388fdda4e0 100644
--- a/wlantest/rx_eapol.c
+++ b/wlantest/rx_eapol.c
@@ -722,8 +722,8 @@ static void rx_data_eapol_key_3_of_4(struct wlantest *wt, const u8 *dst,
 			}
 			p += 2 + p[1];
 		}
-		if (p && p > decrypted && *p == 0xdd &&
-		    p + 1 == decrypted + decrypted_len) {
+		if (p && p > decrypted && p + 1 == decrypted + decrypted_len &&
+		    *p == 0xdd) {
 			/* Remove padding */
 			p--;
 			plain_len = p - decrypted;
-- 
2.28.0.220.ged08abb693-goog