[PATCH AUTOSEL 4.4 07/11] nl80211: fix null pointer dereference

[PATCH AUTOSEL 4.4 07/11] nl80211: fix null pointer dereference

[Sasha Levin]

From: Miaoqing Pan <miaoqing@codeaurora.org>

[ Upstream commit b501426cf86e70649c983c52f4c823b3c40d72a3 ]

If the interface is not in MESH mode, the command 'iw wlanx mpath del'
will cause kernel panic.

The root cause is null pointer access in mpp_flush_by_proxy(), as the
pointer 'sdata->u.mesh.mpp_paths' is NULL for non MESH interface.

Unable to handle kernel NULL pointer dereference at virtual address 00000068
[...]
PC is at _raw_spin_lock_bh+0x20/0x5c
LR is at mesh_path_del+0x1c/0x17c [mac80211]
[...]
Process iw (pid: 4537, stack limit = 0xd83e0238)
[...]
[<c021211c>] (_raw_spin_lock_bh) from [<bf8c7648>] (mesh_path_del+0x1c/0x17c [mac80211])
[<bf8c7648>] (mesh_path_del [mac80211]) from [<bf6cdb7c>] (extack_doit+0x20/0x68 [compat])
[<bf6cdb7c>] (extack_doit [compat]) from [<c05c309c>] (genl_rcv_msg+0x274/0x30c)
[<c05c309c>] (genl_rcv_msg) from [<c05c25d8>] (netlink_rcv_skb+0x58/0xac)
[<c05c25d8>] (netlink_rcv_skb) from [<c05c2e14>] (genl_rcv+0x20/0x34)
[<c05c2e14>] (genl_rcv) from [<c05c1f90>] (netlink_unicast+0x11c/0x204)
[<c05c1f90>] (netlink_unicast) from [<c05c2420>] (netlink_sendmsg+0x30c/0x370)
[<c05c2420>] (netlink_sendmsg) from [<c05886d0>] (sock_sendmsg+0x70/0x84)
[<c05886d0>] (sock_sendmsg) from [<c0589f4c>] (___sys_sendmsg.part.3+0x188/0x228)
[<c0589f4c>] (___sys_sendmsg.part.3) from [<c058add4>] (__sys_sendmsg+0x4c/0x70)
[<c058add4>] (__sys_sendmsg) from [<c0208c80>] (ret_fast_syscall+0x0/0x44)
Code: e2822c02 e2822001 e5832004 f590f000 (e1902f9f)
---[ end trace bbd717600f8f884d ]---

Signed-off-by: Miaoqing Pan <miaoqing@codeaurora.org>
Link: https://lore.kernel.org/r/1569485810-761-1-git-send-email-miaoqing@codeaurora.org
[trim useless data from commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/wireless/nl80211.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 1968998e6c6c2..4c9fc29ee1edf 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4779,6 +4779,9 @@ static int nl80211_del_mpath(struct sk_buff *skb, struct genl_info *info)
 	if (!rdev->ops->del_mpath)
 		return -EOPNOTSUPP;
 
+	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
+		return -EOPNOTSUPP;
+
 	return rdev_del_mpath(rdev, dev, dst);
 }
 
-- 
2.20.1

[PATCH AUTOSEL 4.4 09/11] net: hisilicon: Fix usage of uninitialized variable in function mdio_sc_cfg_reg_write()

[Sasha Levin]

From: Yizhuo <yzhai003@ucr.edu>

[ Upstream commit 53de429f4e88f538f7a8ec2b18be8c0cd9b2c8e1 ]

In function mdio_sc_cfg_reg_write(), variable "reg_value" could be
uninitialized if regmap_read() fails. However, "reg_value" is used
to decide the control flow later in the if statement, which is
potentially unsafe.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/hisilicon/hns_mdio.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hns_mdio.c b/drivers/net/ethernet/hisilicon/hns_mdio.c
index 6ff13c559e527..09fcc821b7da9 100644
--- a/drivers/net/ethernet/hisilicon/hns_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hns_mdio.c
@@ -156,11 +156,15 @@ static int mdio_sc_cfg_reg_write(struct hns_mdio_device *mdio_dev,
 {
 	u32 time_cnt;
 	u32 reg_value;
+	int ret;
 
 	regmap_write(mdio_dev->subctrl_vbase, cfg_reg, set_val);
 
 	for (time_cnt = MDIO_TIMEOUT; time_cnt; time_cnt--) {
-		regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
+		ret = regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
+		if (ret)
+			return ret;
+
 		reg_value &= st_msk;
 		if ((!!check_st) == (!!reg_value))
 			break;
-- 
2.20.1