wifi: cfg80211: Annotate struct cfg80211_pmsr_request with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct cfg80211_pmsr_request.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20230817211531.4193219-4-keescook@chromium.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Kees Cook 2023-08-17 14:15:26 -07:00 committed by Johannes Berg
parent c14679d700
commit 342bc7c9e8
2 changed files with 2 additions and 3 deletions

View File

@ -3948,7 +3948,7 @@ struct cfg80211_pmsr_request {
struct list_head list;
struct cfg80211_pmsr_request_peer peers[];
struct cfg80211_pmsr_request_peer peers[] __counted_by(n_peers);
};
/**

View File

@ -291,6 +291,7 @@ int nl80211_pmsr_start(struct sk_buff *skb, struct genl_info *info)
req = kzalloc(struct_size(req, peers, count), GFP_KERNEL);
if (!req)
return -ENOMEM;
req->n_peers = count;
if (info->attrs[NL80211_ATTR_TIMEOUT])
req->timeout = nla_get_u32(info->attrs[NL80211_ATTR_TIMEOUT]);
@ -321,8 +322,6 @@ int nl80211_pmsr_start(struct sk_buff *skb, struct genl_info *info)
goto out_err;
idx++;
}
req->n_peers = count;
req->cookie = cfg80211_assign_cookie(rdev);
req->nl_portid = info->snd_portid;