[PATCH AUTOSEL 4.9 24/87] wil6210: check null pointer in _wil_cfg80211_merge_extra_ies

Sasha Levin
2019-03-27T18:21:28Z

From: Alexei Avshalom Lazar <ailizaro@codeaurora.org>

[ Upstream commit de77a53c2d1e8fb3621e63e8e1f0f0c9a1a99ff7 ]

ies1 or ies2 might be null when code inside
_wil_cfg80211_merge_extra_ies access them.
Add explicit check for null and make sure ies1/ies2 are not
accessed in such a case.

spos might be null and be accessed inside
_wil_cfg80211_merge_extra_ies.
Add explicit check for null in the while condition statement
and make sure spos is not accessed in such a case.

Signed-off-by: Alexei Avshalom Lazar <ailizaro@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/wil6210/cfg80211.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/wil6210/cfg80211.c b/drivers/net/wireless/ath/wil6210/cfg80211.c
index d117240d9a73..b8eeaef17edc 100644
--- a/drivers/net/wireless/ath/wil6210/cfg80211.c
+++ b/drivers/net/wireless/ath/wil6210/cfg80211.c
@@ -1005,6 +1005,12 @@ static int _wil_cfg80211_merge_extra_ies(const u8 *ies1, u16 ies1_len,
u8 *buf, *dpos;
const u8 *spos;

+ if (!ies1)
+ ies1_len = 0;
+
+ if (!ies2)
+ ies2_len = 0;
+
if (ies1_len == 0 && ies2_len == 0) {
*merged_ies = NULL;
*merged_len = 0;
@@ -1014,17 +1020,19 @@ static int _wil_cfg80211_merge_extra_ies(const u8 *ies1, u16 ies1_len,
buf = kmalloc(ies1_len + ies2_len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
- memcpy(buf, ies1, ies1_len);
+ if (ies1)
+ memcpy(buf, ies1, ies1_len);
dpos = buf + ies1_len;
spos = ies2;
- while (spos + 1 < ies2 + ies2_len) {
+ while (spos && (spos + 1 < ies2 + ies2_len)) {
/* IE tag at offset 0, length at offset 1 */
u16 ielen = 2 + spos[1];

if (spos + ielen > ies2 + ies2_len)
break;
if (spos[0] == WLAN_EID_VENDOR_SPECIFIC &&
- !_wil_cfg80211_find_ie(ies1, ies1_len, spos, ielen)) {
+ (!ies1 || !_wil_cfg80211_find_ie(ies1, ies1_len,
+ spos, ielen))) {
memcpy(dpos, spos, ielen);
dpos += ielen;
}
--
2.19.1