[PATCH AUTOSEL 5.4 208/330] brcmfmac: Fix double freeing in the fmac usb data path

From: Sasha Levin
Date: Thu Sep 17 2020 - 23:01:09 EST

From: Raveendran Somu <raveendran.somu@xxxxxxxxxxx>

[ Upstream commit 78179869dc3f5c0059bbf5d931a2717f1ad97ecd ]

When the brcmf_fws_process_skb() fails to get hanger slot for
queuing the skb, it tries to free the skb.
But the caller brcmf_netdev_start_xmit() of that funciton frees
the packet on error return value.
This causes the double freeing and which caused the kernel crash.

Signed-off-by: Raveendran Somu <raveendran.somu@xxxxxxxxxxx>
Signed-off-by: Chi-hsien Lin <chi-hsien.lin@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1585124429-97371-3-git-send-email-chi-hsien.lin@xxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
index eadc64454839d..3d36b6ee158bb 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
@@ -2149,8 +2149,7 @@ int brcmf_fws_process_skb(struct brcmf_if *ifp, struct sk_buff *skb)
brcmf_fws_enq(fws, BRCMF_FWS_SKBSTATE_DELAYED, fifo, skb);
} else {
- bphy_err(drvr, "drop skb: no hanger slot\n");
- brcmf_txfinalize(ifp, skb, false);
+ bphy_err(drvr, "no hanger slot available\n");
rc = -ENOMEM;