[PATCH] rtl8188eu: Fix a possible sleep-in-atomic bug in set_tx_beacon_cmd

From: Jia-Ju Bai
Date: Tue Dec 12 2017 - 08:06:05 EST


The driver may sleep under a spinlock.
The function call path is:
update_beacon (acquire the spinlock)
update_BCNTIM
set_tx_beacon_cmd
kzalloc(GFP_KERNEL) --> may sleep
kmemdup(GFP_KERNEL) --> may sleep

To fix it, GFP_KERNEL is replaced with GFP_ATOMIC.

This bug is found by my static analysis tool(DSAC) and checked by my code review.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/staging/rtl8188eu/core/rtw_mlme_ext.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c b/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c
index d73e9bd..bcb6919 100644
--- a/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c
+++ b/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c
@@ -5395,14 +5395,14 @@ u8 set_tx_beacon_cmd(struct adapter *padapter)
int len_diff = 0;


- ph2c = kzalloc(sizeof(struct cmd_obj), GFP_KERNEL);
+ ph2c = kzalloc(sizeof(struct cmd_obj), GFP_ATOMIC);
if (!ph2c) {
res = _FAIL;
goto exit;
}

ptxBeacon_parm = kmemdup(&(pmlmeinfo->network),
- sizeof(struct wlan_bssid_ex), GFP_KERNEL);
+ sizeof(struct wlan_bssid_ex), GFP_ATOMIC);
if (ptxBeacon_parm == NULL) {
kfree(ph2c);
res = _FAIL;
--
1.7.9.5