From: Jia-Ju Bai <baijiaju1990@163.com>
Date: Wed, 31 May 2017 07:08:25 +0000 (+0800)
Subject: mISDN: Fix a sleep-in-atomic bug
X-Git-Tag: v3.18.105~60
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8fe9dcbadf023b3ced2a2cc7ad572c8d97f8fff4;p=linux

mISDN: Fix a sleep-in-atomic bug


[ Upstream commit 93818da5eed63fbc17b64080406ea53b86b23309 ]

The driver may sleep under a read spin lock, and the function call path is:
send_socklist (acquire the lock by read_lock)
  skb_copy(GFP_KERNEL) --> may sleep

To fix it, the "GFP_KERNEL" is replaced with "GFP_ATOMIC".

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/isdn/mISDN/stack.c b/drivers/isdn/mISDN/stack.c
index 9cb4b621fbc3..b92a19a594a1 100644
--- a/drivers/isdn/mISDN/stack.c
+++ b/drivers/isdn/mISDN/stack.c
@@ -72,7 +72,7 @@ send_socklist(struct mISDN_sock_list *sl, struct sk_buff *skb)
 		if (sk->sk_state != MISDN_BOUND)
 			continue;
 		if (!cskb)
-			cskb = skb_copy(skb, GFP_KERNEL);
+			cskb = skb_copy(skb, GFP_ATOMIC);
 		if (!cskb) {
 			printk(KERN_WARNING "%s no skb\n", __func__);
 			break;