From: Stefan Richter <stefanr@s5r6.in-berlin.de>
Date: Tue, 18 Feb 2014 21:25:15 +0000 (+0100)
Subject: firewire: net: fix use after free
X-Git-Tag: v3.14-rc6~13^2~1
X-Git-Url: http://git.cascardo.eti.br/?a=commitdiff_plain;h=8987583366ae9e03c306c2b7d73bdb952df1d08d;p=cascardo%2Flinux.git

firewire: net: fix use after free

Commit 8408dc1c14c1 "firewire: net: use dev_printk API" introduced a
use-after-free in a failure path.  fwnet_transmit_packet_failed(ptask)
may free ptask, then the dev_err() call dereferenced it.  The fix is
straightforward; simply reorder the two calls.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---

diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index 6b895986dc22..4af0a7bad7f2 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -929,8 +929,6 @@ static void fwnet_write_complete(struct fw_card *card, int rcode,
 	if (rcode == RCODE_COMPLETE) {
 		fwnet_transmit_packet_done(ptask);
 	} else {
-		fwnet_transmit_packet_failed(ptask);
-
 		if (printk_timed_ratelimit(&j,  1000) || rcode != last_rcode) {
 			dev_err(&ptask->dev->netdev->dev,
 				"fwnet_write_complete failed: %x (skipped %d)\n",
@@ -938,8 +936,10 @@ static void fwnet_write_complete(struct fw_card *card, int rcode,
 
 			errors_skipped = 0;
 			last_rcode = rcode;
-		} else
+		} else {
 			errors_skipped++;
+		}
+		fwnet_transmit_packet_failed(ptask);
 	}
 }