[3.11.y.z extended stable] Patch "bnx2x: fix possible panic under memory stress" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    bnx2x: fix possible panic under memory stress

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 0041c094500544da8360bc5147a315b68b817c00 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet at google.com>
Date: Thu, 26 Jun 2014 00:44:02 -0700
Subject: bnx2x: fix possible panic under memory stress

commit 07b0f00964def8af9321cfd6c4a7e84f6362f728 upstream.

While it is legal to kfree(NULL), it is not wise to use :
put_page(virt_to_head_page(NULL))

 BUG: unable to handle kernel paging request at ffffeba400000000
 IP: [<ffffffffc01f5928>] virt_to_head_page+0x36/0x44 [bnx2x]

Reported-by: Michel Lespinasse <walken at google.com>
Signed-off-by: Eric Dumazet <edumazet at google.com>
Cc: Ariel Elior <ariel.elior at qlogic.com>
Fixes: d46d132cc021 ("bnx2x: use netdev_alloc_frag()")
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 6e49403d6ec5..5fedcb6d7ec0 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -750,7 +750,8 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp,

 		return;
 	}
-	bnx2x_frag_free(fp, new_data);
+	if (new_data)
+		bnx2x_frag_free(fp, new_data);
 drop:
 	/* drop the packet and keep the buffer in the bin */
 	DP(NETIF_MSG_RX_STATUS,
--
1.9.1