[PATCH 4.9 15/56] mac80211_hwsim: Fix a possible sleep-in-atomic bug in hwsim_get_radio_nl

Greg Kroah-Hartman
2018-03-02T08:51:01Z

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/mac80211_hwsim.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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_
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;