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@xxxxxxxxxxxxxxx # 4.10.x, 4.9.x
Reported-by: Daniel J Blueman <daniel@xxxxxxxxx>
Reviewed-by: Hante Meuleman <hante.meuleman@xxxxxxxxxxxx>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@xxxxxxxxxxxx>
Reviewed-by: Franky Lin <franky.lin@xxxxxxxxxxxx>
Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
---
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 de19c7c..85d949e 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;
--
1.9.1
