ath11k: Avoid memcpy() over-reading of he_cap

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring array fields.

Since peer_he_cap_{mac,phy}info and he_cap_elem.{mac,phy}_cap_info are not
the same sizes, memcpy() was reading beyond field boundaries. Instead,
correctly cap the copy length and pad out any difference in size
(peer_he_cap_macinfo is 8 bytes whereas mac_cap_info is 6, and
peer_he_cap_phyinfo is 12 bytes whereas phy_cap_info is 11).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210616195410.1232119-1-keescook@chromium.org

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index eb52332..e9b3689 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -1314,10 +1314,16 @@ static void ath11k_peer_assoc_h_he(struct ath11k *ar,
 
        arg->he_flag = true;
 
-       memcpy(&arg->peer_he_cap_macinfo, he_cap->he_cap_elem.mac_cap_info,
-              sizeof(arg->peer_he_cap_macinfo));
-       memcpy(&arg->peer_he_cap_phyinfo, he_cap->he_cap_elem.phy_cap_info,
-              sizeof(arg->peer_he_cap_phyinfo));
+       memcpy_and_pad(&arg->peer_he_cap_macinfo,
+                      sizeof(arg->peer_he_cap_macinfo),
+                      he_cap->he_cap_elem.mac_cap_info,
+                      sizeof(he_cap->he_cap_elem.mac_cap_info),
+                      0);
+       memcpy_and_pad(&arg->peer_he_cap_phyinfo,
+                      sizeof(arg->peer_he_cap_phyinfo),
+                      he_cap->he_cap_elem.phy_cap_info,
+                      sizeof(he_cap->he_cap_elem.phy_cap_info),
+                      0);
        arg->peer_he_ops = vif->bss_conf.he_oper.params;
 
        /* the top most byte is used to indicate BSS color info */