[PATCH 4.9 109/138] mwifiex: sdio: fix use after free issue for save_adapter

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Amitkumar Karwar <akarwar@xxxxxxxxxxx>


[ Upstream commit 74c8719b8ee0922593a5cbec0bd6127d86d8a2f4 ]

If we have sdio work requests received when sdio card reset is
happening, we may end up accessing older save_adapter pointer
later which is already freed during card reset.
This patch solves the problem by cancelling those pending requests.

Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/wireless/marvell/mwifiex/sdio.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/net/wireless/marvell/mwifiex/sdio.c
+++ b/drivers/net/wireless/marvell/mwifiex/sdio.c
@@ -2296,6 +2296,12 @@ static void mwifiex_recreate_adapter(str
 	mmc_hw_reset(func->card->host);
 	sdio_release_host(func);
 
+	/* Previous save_adapter won't be valid after this. We will cancel
+	 * pending work requests.
+	 */
+	clear_bit(MWIFIEX_IFACE_WORK_DEVICE_DUMP, &iface_work_flags);
+	clear_bit(MWIFIEX_IFACE_WORK_CARD_RESET, &iface_work_flags);
+
 	mwifiex_sdio_probe(func, device_id);
 }