From ba6cb7c0868a412c2eb68e8efd5aa38bfb258a14 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 7 Aug 2026 11:52:30 +0000 Subject: wifi: wilc1000: fix out-of-bounds read in P2P public action frames wilc_wfi_p2p_rx() and mgmt_tx() start parsing a frame once ieee80211_is_public_action() returns true. That helper only verifies the frame is long enough for the action category field, that is offsetofend(struct ieee80211_mgmt, u.action.category), 25 bytes. Both functions then read the P2P public action header up to oui_subtype at offset 30 and pass "size - ie_offset" to cfg80211_find_vendor_ie(), where ie_offset is offsetof(struct ieee80211_mgmt, u) + sizeof(*d), i.e. 32. A public action frame of 25 to 31 bytes passes the check but is shorter than that 32 byte header, so oui_subtype can be read out of bounds, and because the length is unsigned, "size - ie_offset" underflows to a value close to 4 GiB. cfg80211_find_vendor_ie() takes an unsigned int length, so even the size_t subtraction in mgmt_tx() is truncated to the same value. It then walks far past the buffer searching for a vendor element until it reaches unmapped memory. In the receive path the frame arrives over the air and needs no association, so a nearby unauthenticated device can crash the host while it is in P2P listen. Reject frames shorter than the P2P public action header in both paths before dereferencing it. Fixes: 4fb8b5aa2a11 ("staging: wilc1000: refactor p2p action frames handling API's") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Link: https://patch.msgid.link/20260807115230.136767-1-ali@iusegentoo.com Signed-off-by: Johannes Berg --- drivers/net/wireless/microchip/wilc1000/cfg80211.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/net/wireless/microchip/wilc1000/cfg80211.c b/drivers/net/wireless/microchip/wilc1000/cfg80211.c index bb2748a19329..9ad21d41e999 100644 --- a/drivers/net/wireless/microchip/wilc1000/cfg80211.c +++ b/drivers/net/wireless/microchip/wilc1000/cfg80211.c @@ -1058,6 +1058,13 @@ void wilc_wfi_p2p_rx(struct wilc_vif *vif, u8 *buff, u32 size) if (!ieee80211_is_public_action((struct ieee80211_hdr *)buff, size)) goto out_rx_mgmt; + /* ieee80211_is_public_action() only validates up to the category + * byte, so reject frames too short for the P2P public action header + * before dereferencing it or computing size - ie_offset. + */ + if (size < ie_offset) + goto out_rx_mgmt; + d = (struct wilc_p2p_pub_act_frame *)(&mgmt->u.action); if (d->oui_subtype != GO_NEG_REQ && d->oui_subtype != GO_NEG_RSP && d->oui_subtype != P2P_INV_REQ && d->oui_subtype != P2P_INV_RSP) @@ -1200,6 +1207,13 @@ static int mgmt_tx(struct wiphy *wiphy, goto out_set_timeout; } + /* ieee80211_is_public_action() only validates up to the category + * byte, so reject frames too short for the P2P public action header + * before dereferencing it or computing len - ie_offset. + */ + if (len < ie_offset) + goto out_set_timeout; + d = (struct wilc_p2p_pub_act_frame *)(&mgmt->u.action); if (d->oui_type != WLAN_OUI_TYPE_WFA_P2P || d->oui_subtype != GO_NEG_CONF) { -- cgit v1.2.3