[PATCH 4.20 05/57] staging: rtl8188eu: Fix module loading from tasklet for WEP encryption

From: Greg Kroah-Hartman
Date: Tue Jan 15 2019 - 11:52:14 EST


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

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

From: Larry Finger <Larry.Finger@xxxxxxxxxxxx>

commit 7775665aadc48a562051834a73519129bf717d73 upstream.

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@xxxxxxxxxxxxxxx> # v4.17+
Cc: Michael Straube <straube.linux@xxxxxxxxx>
Cc: Ivan Safonov <insafonov@xxxxxxxxx>
Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/staging/rtl8188eu/core/rtw_security.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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 *pad

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 *pad
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) {