2018-09-15 02:59:18

by Jia-Ju Bai

[permalink] [raw]
Subject: [PATCH] staging: rtl8188eu: Fix a sleep-in-atomic-context bug in issue_deauth_ex()

The driver may sleep with holding a spinlock.
The function call path (from bottom to top) in Linux-4.17 is:

[FUNC] msleep
drivers/staging/rtl8188eu/core/rtw_mlme_ext.c, 1536:
msleep in issue_deauth_ex
drivers/staging/rtl8188eu/core/rtw_mlme_ext.c, 5110:
issue_deauth_ex in disconnect_hdl
drivers/staging/rtl8188eu/core/rtw_cmd.c, 521:
disconnect_hdl in rtw_disassoc_cmd
drivers/staging/rtl8188eu/core/rtw_ioctl_set.c, 352:
rtw_disassoc_cmd in rtw_set_802_11_infrastructure_mode
drivers/staging/rtl8188eu/os_dep/ioctl_linux.c, 1002:
rtw_set_802_11_infrastructure_mode in rtw_wx_set_wap
drivers/staging/rtl8188eu/os_dep/ioctl_linux.c, 988:
spin_lock_bh in rtw_wx_set_wap

To fix this bug, msleep() is replaced with mdelay().

This bug is found by my static analysis tool DSAC.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/staging/rtl8188eu/core/rtw_mlme_ext.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c b/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c
index 1115050077e4..f47d83e6dfb9 100644
--- a/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c
+++ b/drivers/staging/rtl8188eu/core/rtw_mlme_ext.c
@@ -1513,7 +1513,7 @@ static int issue_deauth_ex(struct adapter *padapter, u8 *da,
break;

if (i < try_cnt && wait_ms > 0 && ret == _FAIL)
- msleep(wait_ms);
+ mdelay(wait_ms);
} while ((i < try_cnt) && ((ret == _FAIL) || (wait_ms == 0)));

if (ret != _FAIL) {
--
2.17.0