From b756862459d2b8a977538e5f61345e3633c51d0f Mon Sep 17 00:00:00 2001
From: Jia-Ju Bai <baijiaju1990@163.com>
Date: Wed, 31 May 2017 09:40:11 +0800
Subject: isdn: Fix a sleep-in-atomic bug

commit e8f4ae85439f34bec3b0ab69223a41809dab28c9 upstream.

The driver may sleep under a spin lock, the function call path is:
isdn_ppp_mp_receive (acquire the lock)
  isdn_ppp_mp_reassembly
    isdn_ppp_push_higher
      isdn_ppp_decompress
        isdn_ppp_ccp_reset_trans
          isdn_ppp_ccp_reset_alloc_state
            kzalloc(GFP_KERNEL) --> may sleep

To fixed 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: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index 9c1e8ad..bf3fbd0 100644
--- a/drivers/isdn/i4l/isdn_ppp.c
+++ b/drivers/isdn/i4l/isdn_ppp.c
@@ -2364,7 +2364,7 @@ static struct ippp_ccp_reset_state *isdn_ppp_ccp_reset_alloc_state(struct ippp_s
 		       id);
 		return NULL;
 	} else {
-		rs = kzalloc(sizeof(struct ippp_ccp_reset_state), GFP_KERNEL);
+		rs = kzalloc(sizeof(struct ippp_ccp_reset_state), GFP_ATOMIC);
 		if (!rs)
 			return NULL;
 		rs->state = CCPResetIdle;
-- 
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