[PATCH] cfg80211: read wmm rules from regulatory database

From: Haim Dreyfuss
Date: Wed Mar 28 2018 - 06:24:09 EST

specifically in function: reg_copy_regd()

+ for (i = 0; i < src_regd->n_reg_rules; i++) {
memcpy(&regd->reg_rules[i], &src_regd->reg_rules[i],
sizeof(struct ieee80211_reg_rule));
+ if (!src_regd->reg_rules[i].wmm_rule)
+ continue;

+ regd->reg_rules[i].wmm_rule = d_wmm +
+ (src_regd->reg_rules[i].wmm_rule - s_wmm) /
+ sizeof(struct ieee80211_wmm_rule);
+ }

The pointer arithmetic (src_regd->reg_rules[i].wmm_rule - s_wmm) is
performed in terms of the size of struct ieee80211_wmm_rule and not in
bytes and I believe that the division by sizeof(struct
ieee80211_wmm_rule) is not required.

This issue was detected by static analysis with Coverity Scan,
CID#1467451 ("Extra sizeof expression"), 'suspicious_division'

I'm not 100% sure that is this a false positive or not, but I think it
looks incorrect to me.