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* [PATCH] mwifiex: fix null pointer deference when adapter is null
@ 2016-09-15 13:42 Colin King
  2016-09-15 13:56 ` Julian Calaby
  2016-09-15 16:29 ` kbuild test robot
  0 siblings, 2 replies; 4+ messages in thread
From: Colin King @ 2016-09-15 13:42 UTC (permalink / raw)
  To: Amitkumar Karwar, Nishant Sarmukadam, Kalle Valo, linux-wireless,
	netdev
  Cc: linux-kernel

From: Colin Ian King <colin.king@canonical.com>

If adapter is null the error exit path in mwifiex_shutdown_sw is
to down the semaphore sem and print some debug via mwifiex_dbg.
However, passing a NULL adapter to mwifiex_dbg causes a null
pointer deference when accessing adapter->dev.  This fix checks
for a null adapter at the start of the function and to exit
without the need to up the semaphore and we also skip the debug
to avoid the null pointer dereference.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/wireless/marvell/mwifiex/main.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/main.c b/drivers/net/wireless/marvell/mwifiex/main.c
index 9b2e98c..7a4f8cc 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.c
+++ b/drivers/net/wireless/marvell/mwifiex/main.c
@@ -1369,12 +1369,12 @@ mwifiex_shutdown_sw(struct mwifiex_adapter *adapter, struct semaphore *sem)
 	struct mwifiex_private *priv;
 	int i;
 
+	if (!adapter)
+		goto exit_return;
+
 	if (down_interruptible(sem))
 		goto exit_sem_err;
 
-	if (!adapter)
-		goto exit_remove;
-
 	priv = mwifiex_get_priv(adapter, MWIFIEX_BSS_ROLE_ANY);
 	mwifiex_deauthenticate(priv, NULL);
 
@@ -1434,6 +1434,7 @@ mwifiex_shutdown_sw(struct mwifiex_adapter *adapter, struct semaphore *sem)
 	up(sem);
 exit_sem_err:
 	mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__);
+exit_return:
 	return 0;
 }
 
-- 
2.9.3

^ permalink raw reply related	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-09-16  3:56 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-09-15 13:42 [PATCH] mwifiex: fix null pointer deference when adapter is null Colin King
2016-09-15 13:56 ` Julian Calaby
2016-09-15 16:29 ` kbuild test robot
     [not found]   ` <201609160029.fRGnTGuA%fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2016-09-16  3:56     ` Kalle Valo

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