[PATCH 4.19 098/422] mwifex: free rx_cmd skb in suspended state

From: Greg Kroah-Hartman
Date: Tue Nov 19 2019 - 01:09:10 EST

From: Ganapathi Bhat <gbhat@xxxxxxxxxxx>

[ Upstream commit 33a164fa8a4c91408e0b7738f754cb1a7827c5f2 ]

USB suspend handler will kill the presubmitted rx_cmd URB. This
triggers a call to the corresponding URB complete handler, which
will free the rx_cmd skb, associated with rx_cmd URB. Due to a
possible race betwen suspend handler and main thread, depicted in
'commit bfcacac6c84b ("mwifiex: do no submit URB in suspended
state")', it is possible that the rx_cmd skb will fail to get
freed. This causes a memory leak, since the resume handler will
always allocate a new rx_cmd skb.

To fix this, free the rx_cmd skb in mwifiex_usb_submit_rx_urb, if
the device is in suspended state.

Signed-off-by: Vidya Dharmaraju <vidyad@xxxxxxxxxxx>
Signed-off-by: Cathy Luo <cluo@xxxxxxxxxxx>
Signed-off-by: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/net/wireless/marvell/mwifiex/usb.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c
index 76d80fd545236..d445acc4786b7 100644
--- a/drivers/net/wireless/marvell/mwifiex/usb.c
+++ b/drivers/net/wireless/marvell/mwifiex/usb.c
@@ -299,6 +299,12 @@ static int mwifiex_usb_submit_rx_urb(struct urb_context *ctx, int size)
struct usb_card_rec *card = (struct usb_card_rec *)adapter->card;

if (test_bit(MWIFIEX_IS_SUSPENDED, &adapter->work_flags)) {
+ if (card->rx_cmd_ep == ctx->ep) {
+ mwifiex_dbg(adapter, INFO, "%s: free rx_cmd skb\n",
+ __func__);
+ dev_kfree_skb_any(ctx->skb);
+ ctx->skb = NULL;
+ }
mwifiex_dbg(adapter, ERROR,
"%s: card removed/suspended, EP %d rx_cmd URB submit skipped\n",
__func__, ctx->ep);