The cfg80211_scan_request structure is followed by a flexible array member as well as several other arrays that are then stored into pointers in the structure. These are allocated currently using a simple sequence of multiplications. Replace the calculations with struct_size(), size_add(), and array_size() helper macros. These macros saturate the calculation at SIZE_MAX rather than overflowing. Note that we can't use flex_array_size() instead of array_size() because the fields are not arrays, but simple pointers. Signed-off-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> --- This was discovered by a coccinelle patch I developed, and submitted at: https://lore.kernel.org/all/20230227202428.3657443-1-jacob.e.keller@xxxxxxxxx/ V1: https://lore.kernel.org/linux-wireless/99a9d4a2-d032-1c9d-90c6-3a68f6b3a092@xxxxxxxxx/ Changes since v1 * Split series into individual postings to avoid confusion about dependency net/wireless/nl80211.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 112b4bb009c8..e5b08546bf30 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -9019,7 +9019,7 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) struct nlattr *attr; struct wiphy *wiphy; int err, tmp, n_ssids = 0, n_channels, i; - size_t ie_len; + size_t ie_len, size; wiphy = &rdev->wiphy; @@ -9064,10 +9064,10 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) if (ie_len > wiphy->max_scan_ie_len) return -EINVAL; - request = kzalloc(sizeof(*request) - + sizeof(*request->ssids) * n_ssids - + sizeof(*request->channels) * n_channels - + ie_len, GFP_KERNEL); + size = struct_size(request, channels, n_channels); + size = size_add(size, array_size(sizeof(*request->ssids), n_ssids)); + size = size_add(size, ie_len); + request = kzalloc(size, GFP_KERNEL); if (!request) return -ENOMEM; @@ -9400,7 +9400,7 @@ nl80211_parse_sched_scan(struct wiphy *wiphy, struct wireless_dev *wdev, struct nlattr *attr; int err, tmp, n_ssids = 0, n_match_sets = 0, n_channels, i, n_plans = 0; enum nl80211_band band; - size_t ie_len; + size_t ie_len, size; struct nlattr *tb[NL80211_SCHED_SCAN_MATCH_ATTR_MAX + 1]; s32 default_match_rssi = NL80211_SCAN_RSSI_THOLD_OFF; @@ -9509,12 +9509,14 @@ nl80211_parse_sched_scan(struct wiphy *wiphy, struct wireless_dev *wdev, attrs[NL80211_ATTR_SCHED_SCAN_RSSI_ADJUST])) return ERR_PTR(-EINVAL); - request = kzalloc(sizeof(*request) - + sizeof(*request->ssids) * n_ssids - + sizeof(*request->match_sets) * n_match_sets - + sizeof(*request->scan_plans) * n_plans - + sizeof(*request->channels) * n_channels - + ie_len, GFP_KERNEL); + size = struct_size(request, channels, n_channels); + size = size_add(size, array_size(sizeof(*request->ssids), n_ssids)); + size = size_add(size, array_size(sizeof(*request->match_sets), + n_match_sets)); + size = size_add(size, array_size(sizeof(*request->scan_plans), + n_plans)); + size = size_add(size, ie_len); + request = kzalloc(size, GFP_KERNEL); if (!request) return ERR_PTR(-ENOMEM); base-commit: 8f9850dd8d23c1290cb642ce9548a440da5771ec -- 2.39.1.405.gd4c25cc71f83
