[PATCH 0/2] Fixes for system freezes for r8188eu

[PATCH 0/2] Fixes for system freezes for r8188eu

[Larry Finger]

The driver issues "scheduling while atomic" messages and will freeze the
system. These problems are due to attempting to dynamically load library
encryption routines from a tasklet. The fixes are relatively simple. All
that is needed is to replace indirect calls of the try_then_request_module()
macro with a direct call to lib80211_get_crypto_ops(), which forces a load
of the lib80211 module when the wifi driver is loaded.

There will be a similar patch for TKIP encryption; however, the faulty
patch has already been reverted, thus a fix to use the lib80211 routine
directly will be more intrusive. My original attempt failed, thus I am
delaying that fix.

Cc: Michael Straube <straube.linux@gmail.com>
Cc: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---
Larry Finger (2):
  staging: rtl8188eu: Fix module loading from tasklet for CCMP
    encryption
  staging: rtl8188eu: Fix module loading from tasklet for WEP encryption

 drivers/staging/rtl8188eu/core/rtw_security.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.16.4

[PATCH 1/2] staging: rtl8188eu: Fix module loading from tasklet for CCMP encryption

[Larry Finger]

Commit 6bd082af7e36 ("staging:r8188eu: use lib80211 CCMP decrypt")
causes scheduling while atomic bugs followed by a hard freeze whenever
the driver tries to connect to a CCMP-encrypted network. Experimentation
showed that the freezes were eliminated when module lib80211 was
preloaded, which can be forced by calling lib80211_get_crypto_ops()
directly rather than indirectly through try_then_request_module().
With this change, no BUG messages are logged.

Fixes: 6bd082af7e36 ("staging:r8188eu: use lib80211 CCMP decrypt")
Cc: Stable <stable@vger.kernel.org> # v4.17+
Reported-and-tested-by: Michael Straube <straube.linux@gmail.com>
Cc: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---
 drivers/staging/rtl8188eu/core/rtw_security.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_security.c b/drivers/staging/rtl8188eu/core/rtw_security.c
index f7407632e80b..052656a22821 100644
--- a/drivers/staging/rtl8188eu/core/rtw_security.c
+++ b/drivers/staging/rtl8188eu/core/rtw_security.c
@@ -1291,7 +1291,7 @@ u32 rtw_aes_decrypt(struct adapter *padapter, u8 *precvframe)
 			struct sk_buff *skb = ((struct recv_frame *)precvframe)->pkt;
 			void *crypto_private = NULL;
 			u8 *key, *pframe = skb->data;
-			struct lib80211_crypto_ops *crypto_ops = try_then_request_module(lib80211_get_crypto_ops("CCMP"), "lib80211_crypt_ccmp");
+			struct lib80211_crypto_ops *crypto_ops = lib80211_get_crypto_ops("CCMP");
 			struct security_priv *psecuritypriv = &padapter->securitypriv;
 			char iv[8], icv[8];
 
-- 
2.16.4

[PATCH 2/2] staging: rtl8188eu: Fix module loading from tasklet for WEP encryption

[Larry Finger]

Commit 2b2ea09e74a5 ("staging:r8188eu: Use lib80211 to decrypt WEP-frames")
causes scheduling while atomic bugs followed by a hard freeze whenever
the driver tries to connect to a WEP-encrypted network. Experimentation
showed that the freezes were eliminated when module lib80211 was
preloaded, which can be forced by calling lib80211_get_crypto_ops()
directly rather than indirectly through try_then_request_module().
With this change, no BUG messages are logged.

Fixes: 2b2ea09e74a5 ("staging:r8188eu: Use lib80211 to decrypt WEP-frames")
Cc: Stable <stable@vger.kernel.org> # v4.17+
Cc: Michael Straube <straube.linux@gmail.com>
Cc: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---
 drivers/staging/rtl8188eu/core/rtw_security.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_security.c b/drivers/staging/rtl8188eu/core/rtw_security.c
index 052656a22821..bab96c870042 100644
--- a/drivers/staging/rtl8188eu/core/rtw_security.c
+++ b/drivers/staging/rtl8188eu/core/rtw_security.c
@@ -154,7 +154,7 @@ void rtw_wep_encrypt(struct adapter *padapter, u8 *pxmitframe)
 
 	pframe = ((struct xmit_frame *)pxmitframe)->buf_addr + hw_hdr_offset;
 
-	crypto_ops = try_then_request_module(lib80211_get_crypto_ops("WEP"), "lib80211_crypt_wep");
+	crypto_ops = lib80211_get_crypto_ops("WEP");
 
 	if (!crypto_ops)
 		return;
@@ -210,7 +210,7 @@ int rtw_wep_decrypt(struct adapter  *padapter, u8 *precvframe)
 		void *crypto_private = NULL;
 		int status = _SUCCESS;
 		const int keyindex = prxattrib->key_index;
-		struct lib80211_crypto_ops *crypto_ops = try_then_request_module(lib80211_get_crypto_ops("WEP"), "lib80211_crypt_wep");
+		struct lib80211_crypto_ops *crypto_ops = lib80211_get_crypto_ops("WEP");
 		char iv[4], icv[4];
 
 		if (!crypto_ops) {
-- 
2.16.4