As part of the work to perform bounds checking on all memcpy() uses, replace the open-coded a deserialization of bytes out of memory into a trailing flexible array by using a flex_array.h helper to perform the allocation, bounds checking, and copying.
Cc: Johannes Berg <johan...@sipsolutions.net> Cc: "David S. Miller" <da...@davemloft.net> Cc: Jakub Kicinski <k...@kernel.org> Cc: Paolo Abeni <pab...@redhat.com> Cc: Eric Dumazet <eduma...@google.com> Cc: linux-wirel...@vger.kernel.org Cc: net...@vger.kernel.org Signed-off-by: Kees Cook <keesc...@chromium.org> --- include/net/cfg80211.h | 4 ++-- net/wireless/scan.c | 21 ++++++--------------- 2 files changed, 8 insertions(+), 17 deletions(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 68713388b617..fa236015f6ef 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -2600,9 +2600,9 @@ struct cfg80211_inform_bss { struct cfg80211_bss_ies { u64 tsf; struct rcu_head rcu_head; - int len; + DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(int, len); bool from_beacon; - u8 data[]; + DECLARE_FLEX_ARRAY_ELEMENTS(u8, data); }; /** diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 4a6d86432910..9f53d05c6aaa 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1932,7 +1932,7 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, gfp_t gfp) { struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy); - struct cfg80211_bss_ies *ies; + struct cfg80211_bss_ies *ies = NULL; struct ieee80211_channel *channel; struct cfg80211_internal_bss tmp = {}, *res; int bss_type; @@ -1978,13 +1978,10 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, * override the IEs pointer should we have received an earlier * indication of Probe Response data. */ - ies = kzalloc(sizeof(*ies) + ielen, gfp); - if (!ies) + if (mem_to_flex_dup(&ies, ie, ielen, gfp)) return NULL; - ies->len = ielen; ies->tsf = tsf; ies->from_beacon = false; - memcpy(ies->data, ie, ielen); switch (ftype) { case CFG80211_BSS_FTYPE_BEACON: @@ -2277,7 +2274,7 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, size_t ielen = len - offsetof(struct ieee80211_mgmt, u.probe_resp.variable); size_t new_ie_len; - struct cfg80211_bss_ies *new_ies; + struct cfg80211_bss_ies *new_ies = NULL; const struct cfg80211_bss_ies *old; u8 cpy_len; @@ -2314,8 +2311,7 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, if (!new_ie) return; - new_ies = kzalloc(sizeof(*new_ies) + new_ie_len, GFP_ATOMIC); - if (!new_ies) + if (mem_to_flex_dup(&new_ies, new_ie, new_ie_len, GFP_ATOMIC)) goto out_free; pos = new_ie; @@ -2333,10 +2329,8 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy, memcpy(pos, mbssid + cpy_len, ((ie + ielen) - (mbssid + cpy_len))); /* update ie */ - new_ies->len = new_ie_len; new_ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); new_ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control); - memcpy(new_ies->data, new_ie, new_ie_len); if (ieee80211_is_probe_resp(mgmt->frame_control)) { old = rcu_access_pointer(nontrans_bss->proberesp_ies); rcu_assign_pointer(nontrans_bss->proberesp_ies, new_ies); @@ -2363,7 +2357,7 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, gfp_t gfp) { struct cfg80211_internal_bss tmp = {}, *res; - struct cfg80211_bss_ies *ies; + struct cfg80211_bss_ies *ies = NULL; struct ieee80211_channel *channel; bool signal_valid; struct ieee80211_ext *ext = NULL; @@ -2442,14 +2436,11 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy, capability = le16_to_cpu(mgmt->u.probe_resp.capab_info); } - ies = kzalloc(sizeof(*ies) + ielen, gfp); - if (!ies) + if (mem_to_flex_dup(&ies, variable, ielen, gfp)) return NULL; - ies->len = ielen; ies->tsf = le64_to_cpu(mgmt->u.probe_resp.timestamp); ies->from_beacon = ieee80211_is_beacon(mgmt->frame_control) || ieee80211_is_s1g_beacon(mgmt->frame_control); - memcpy(ies->data, variable, ielen); if (ieee80211_is_probe_resp(mgmt->frame_control)) rcu_assign_pointer(tmp.pub.proberesp_ies, ies); -- 2.32.0