From d77facb88448cdeaaa3adba5b9704a48ac2ac8d6 Mon Sep 17 00:00:00 2001 From: Arend Van Spriel Date: Tue, 28 Mar 2017 09:11:30 +0100 Subject: [PATCH] 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: Daniel J Blueman Reviewed-by: Hante Meuleman Reviewed-by: Pieter-Paul Giesberts Reviewed-by: Franky Lin Signed-off-by: Arend van Spriel Signed-off-by: Kalle Valo --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c index de19c7c92bc6..85d949e03f79 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c @@ -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; -- 2.20.1