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Commit d77facb8 authored by Arend Van Spriel's avatar Arend Van Spriel Committed by Kalle Valo
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brcmfmac: use local iftype avoiding use-after-free of virtual interface 



A use-after-free was found using KASAN. In brcmf_p2p_del_if() the virtual
interface is removed using call to brcmf_remove_interface(). After that
the virtual interface instance has been freed and should not be referenced.
Solve this by storing the nl80211 iftype in local variable, which is used
in a couple of places anyway.

Cc: stable@vger.kernel.org # 4.10.x, 4.9.x
Reported-by: default avatarDaniel J Blueman <daniel@quora.org>
Reviewed-by: default avatarHante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: default avatarPieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: default avatarFranky Lin <franky.lin@broadcom.com>
Signed-off-by: default avatarArend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent 893dc68f

drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c

+5 −3
Original line number Diff line number Diff line
@@ -2238,14 +2238,16 @@ int brcmf_p2p_del_vif(struct wiphy *wiphy, struct wireless_dev *wdev) 
	struct brcmf_cfg80211_info *cfg = wiphy_priv(wiphy);

	struct brcmf_p2p_info *p2p = &cfg->p2p;

	struct brcmf_cfg80211_vif *vif;

	enum nl80211_iftype iftype;

	bool wait_for_disable = false;

	int err;



	brcmf_dbg(TRACE, "delete P2P vif\n");

	vif = container_of(wdev, struct brcmf_cfg80211_vif, wdev);



	iftype = vif->wdev.iftype;

	brcmf_cfg80211_arm_vif_event(cfg, vif);

	switch (vif->wdev.iftype) {

	switch (iftype) {

	case NL80211_IFTYPE_P2P_CLIENT:

		if (test_bit(BRCMF_VIF_STATUS_DISCONNECTING, &vif->sme_state))

			wait_for_disable = true;
@@ -2275,7 +2277,7 @@ int brcmf_p2p_del_vif(struct wiphy *wiphy, struct wireless_dev *wdev) 
					    BRCMF_P2P_DISABLE_TIMEOUT);



	err = 0;

	if (vif->wdev.iftype != NL80211_IFTYPE_P2P_DEVICE) {

	if (iftype != NL80211_IFTYPE_P2P_DEVICE) {

		brcmf_vif_clear_mgmt_ies(vif);

		err = brcmf_p2p_release_p2p_if(vif);

	}
@@ -2291,7 +2293,7 @@ int brcmf_p2p_del_vif(struct wiphy *wiphy, struct wireless_dev *wdev) 
	brcmf_remove_interface(vif->ifp, true);



	brcmf_cfg80211_arm_vif_event(cfg, NULL);

	if (vif->wdev.iftype != NL80211_IFTYPE_P2P_DEVICE)

	if (iftype != NL80211_IFTYPE_P2P_DEVICE)

		p2p->bss_idx[P2PAPI_BSSCFG_CONNECTION].vif = NULL;



	return err;