From: Xinming Hu <huxm@xxxxxxxxxxx>
card->adapter gets initialized in mwifiex_register_dev(). As it's not
cleared in mwifiex_unregister_dev(), we may end up accessing the memory
which is already free in below scenario.
Scenario: Driver initialization is failed due to incorrect firmware or
some other reason. Meanwhile device reboot/unload occurs.
Please note that we have 'add_remove_card_sem' semaphore. So if there
is a race betweem init and remove threads, they will execute one after
another. This patch ensures that "card->adapter" is set to NULL when
all cleanup is performed in init failure thread. Later remove thread
can return immediately if "card->adapter" is NULL
Signed-off-by: Xinming Hu <huxm@xxxxxxxxxxx>
Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
---
v4: Same as v1, v2, v3
v5: Patch description is updated to get clear picture. There is no race
for init and remove threads as per design. This patch just adds missing
"card->adapter= NULL" change to avoid accessing already freed memory which
leads to a crash.
---
drivers/net/wireless/marvell/mwifiex/pcie.c | 1 +
drivers/net/wireless/marvell/mwifiex/sdio.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c
index 063c707..302ffd1 100644
--- a/drivers/net/wireless/marvell/mwifiex/pcie.c
+++ b/drivers/net/wireless/marvell/mwifiex/pcie.c
@@ -3021,6 +3021,7 @@ static void mwifiex_unregister_dev(struct mwifiex_adapter *adapter)
if (card->msi_enable)
pci_disable_msi(pdev);
}
+ card->adapter = NULL;
}
}
diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c
index 8718950..4cad1c2 100644
--- a/drivers/net/wireless/marvell/mwifiex/sdio.c
+++ b/drivers/net/wireless/marvell/mwifiex/sdio.c
@@ -2066,6 +2066,7 @@ mwifiex_unregister_dev(struct mwifiex_adapter *adapter)
struct sdio_mmc_card *card = adapter->card;
if (adapter->card) {
+ card->adapter = NULL;
sdio_claim_host(card->func);
sdio_disable_func(card->func);
sdio_release_host(card->func);
--
1.9.1
