[PATCH v6] wifi: brcmfmac: cyw: pass PMKID to firmware if present

From: Bogdan Nicolae

Date: Fri Aug 07 2026 - 12:44:58 EST


Zero out auth_status on initialization. Otherwise, garbage will
leak from the stack to the firmware (when ssid is less than 32 bytes
and/or when params->pmkid is set). Then, pass the params->pmkid to the
firmware (without it, the firmware caches a garbage PMKID on successful
authentication and denies a subsequent association request that includes
the PMKID).

Fixes: 66f909308a7c ("wifi: brcmfmac: cyw: support external SAE authentication in station mode")
Signed-off-by: Bogdan Nicolae <bogdan.nicolae@xxxxxxxxx>
Acked-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
---
v6: Fixed diff line number
v5: Fixed line length > 80 chars
v4: Fixed indentation
v3: Added Fixes, Cc: stable, and Acked-by tags
v2: Split into a separate patch

drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c
index 873754be5..2c59b5e57 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c
@@ -200,7 +200,7 @@ brcmf_cyw_external_auth(struct wiphy *wiphy, struct net_device *dev,
{
struct brcmf_if *ifp;
struct brcmf_pub *drvr;
- struct brcmf_auth_req_status_le auth_status;
+ struct brcmf_auth_req_status_le auth_status = {};
int ret = 0;

brcmf_dbg(TRACE, "Enter\n");
@@ -208,6 +208,9 @@ brcmf_cyw_external_auth(struct wiphy *wiphy, struct net_device *dev,
ifp = netdev_priv(dev);
drvr = ifp->drvr;
if (params->status == WLAN_STATUS_SUCCESS) {
+ if (params->pmkid)
+ memcpy(auth_status.pmkid, params->pmkid,
+ WLAN_PMKID_LEN);
auth_status.flags = cpu_to_le16(BRCMF_EXTAUTH_SUCCESS);
} else {
bphy_err(drvr, "External authentication failed: status=%d\n",
--
2.55.0