[PATCH AUTOSEL for 4.9 13/52] mac80211_hwsim: Fix a possible sleep-in-atomic bug in hwsim_get_radio_nl

Sasha Levin
2018-02-03T18:29:10Z

From: Jia-Ju Bai <baijiaju1990@163.com>

[ Upstream commit 162bd5e5fd921785077b5862d8f2ffabe2fe11e5 ]

The driver may sleep under a spinlock.
The function call path is:
hwsim_get_radio_nl (acquire the spinlock)
nlmsg_new(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@163.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/net/wireless/mac80211_hwsim.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 4b462dc21c41..61e85eac706a 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -3154,7 +3154,7 @@ static int hwsim_get_radio_nl(struct sk_buff *msg, struct genl_info *info)
if (!net_eq(wiphy_net(data->hw->wiphy), genl_info_net(info)))
continue;

- skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!skb) {
res = -ENOMEM;
goto out_err;
--
2.11.0