[PATCH 4.4 112/190] mISDN: Fix a sleep-in-atomic bug

From: Greg Kroah-Hartman
Date: Wed Apr 11 2018 - 14:48:34 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jia-Ju Bai <baijiaju1990@xxxxxxx>


[ 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@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/isdn/mISDN/stack.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/isdn/mISDN/stack.c
+++ b/drivers/isdn/mISDN/stack.c
@@ -72,7 +72,7 @@ send_socklist(struct mISDN_sock_list *sl
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;