Patch "isdn: Fix a sleep-in-atomic bug" has been added to the 4.9-stable tree

Patch "isdn: Fix a sleep-in-atomic bug" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    isdn: Fix a sleep-in-atomic bug

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     isdn-fix-a-sleep-in-atomic-bug.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From e8f4ae85439f34bec3b0ab69223a41809dab28c9 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

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

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>

---
 drivers/isdn/i4l/isdn_ppp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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
 		       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;


Patches currently in stable-queue which might be from baijiaju1990@163.com are

queue-4.9/isdn-fix-a-sleep-in-atomic-bug.patch