[PATCH 5.4 196/344] staging: rtl8188: avoid excessive stack usage

Greg Kroah-Hartman
2020-02-21T08:09:41Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit c497ae2077c055b85c1bf04f3d182a84bd8f365b ]

The rtl8188 copy of the os_dep support code causes a
warning about a very significant stack usage in the translate_scan()
function:

drivers/staging/rtl8188eu/os_dep/ioctl_linux.c: In function 'translate_scan':
drivers/staging/rtl8188eu/os_dep/ioctl_linux.c:306:1: error: the frame size of 1560 bytes is larger than 1400 bytes [-Werror=frame-larger-than=]

Use the same trick as in the rtl8723bs copy of the same function, and
allocate it dynamically.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200104214832.558198-1-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/staging/rtl8188eu/os_dep/ioctl_linux.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c b/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c
index ec5835d1aa8ce..9f0418ee75284 100644
--- a/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c
+++ b/drivers/staging/rtl8188eu/os_dep/ioctl_linux.c
@@ -229,18 +229,21 @@ static char *translate_scan(struct adapter *padapter,

/* parsing WPA/WPA2 IE */
{
- u8 buf[MAX_WPA_IE_LEN];
+ u8 *buf;
u8 wpa_ie[255], rsn_ie[255];
u16 wpa_len = 0, rsn_len = 0;
u8 *p;

+ buf = kzalloc(MAX_WPA_IE_LEN, GFP_ATOMIC);
+ if (!buf)
+ return start;
+
rtw_get_sec_ie(pnetwork->network.ies, pnetwork->network.ie_length, rsn_ie, &rsn_len, wpa_ie, &wpa_len);
RT_TRACE(_module_rtl871x_mlme_c_, _drv_info_, ("rtw_wx_get_scan: ssid =%s\n", pnetwork->network.ssid.ssid));
RT_TRACE(_module_rtl871x_mlme_c_, _drv_info_, ("rtw_wx_get_scan: wpa_len =%d rsn_len =%d\n", wpa_len, rsn_len));

if (wpa_len > 0) {
p = buf;
- memset(buf, 0, MAX_WPA_IE_LEN);
p += sprintf(p, "wpa_ie=");
for (i = 0; i < wpa_len; i++)
p += sprintf(p, "%02x", wpa_ie[i]);
@@ -257,7 +260,6 @@ static char *translate_scan(struct adapter *padapter,
}
if (rsn_len > 0) {
p = buf;
- memset(buf, 0, MAX_WPA_IE_LEN);
p += sprintf(p, "rsn_ie=");
for (i = 0; i < rsn_len; i++)
p += sprintf(p, "%02x", rsn_ie[i]);
@@ -271,6 +273,7 @@ static char *translate_scan(struct adapter *padapter,
iwe.u.data.length = rsn_len;
start = iwe_stream_add_point(info, start, stop, &iwe, rsn_ie);
}
+ kfree(buf);
}

{/* parsing WPS IE */
--
2.20.1