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FAILED: patch "[PATCH] vrf: Fix use after free and double free in vrf_finish_output" failed to apply to 4.9-stable tree

PATCH In review [email protected] 4 participants 4 messages Apr 11, 2018

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Network drivers Stable branch VRF
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#0 lore raw

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 82dd0d2a9a76fc8fa2b18d80b987d455728bf83a Mon Sep 17 00:00:00 2001

From: David Ahern <[email protected]>
Date: Thu, 29 Mar 2018 12:49:52 -0700
Subject: [PATCH] vrf: Fix use after free and double free in vrf_finish_output

Miguel reported an skb use after free / double free in vrf_finish_output when neigh_output returns an error. The vrf driver should return after the call to neigh_output as it takes over the skb on error path as well.

Patch is a simplified version of Miguel's patch which was written for 4.9, and updated to top of tree.

Fixes 8f58336d3f78a ("net: Add ethernet header for pass through VRF device")
Signed-off-by Miguel Fadon Perlines <[email protected]>
Signed-off-by David Ahern <[email protected]>
Signed-off-by David S. Miller <[email protected]>
drivers/net/vrf.c +3 -2
index 139c61c8244a..ac40924fe437 100644
@@ -578,12 +578,13 @@ static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *s
 	if (!IS_ERR(neigh)) {
 		sock_confirm_neigh(skb, neigh);
 		ret = neigh_output(neigh, skb);
+		rcu_read_unlock_bh();
+		return ret;
 	}
 
 	rcu_read_unlock_bh();
 err:
-	if (unlikely(ret < 0))
-		vrf_tx_error(skb->dev, skb);
+	vrf_tx_error(skb->dev, skb);
 	return ret;
 }
#1 lore raw

PATCH 1/1 vrf: Fix use after free and double free in vrf_finish_output

[ upstream commit 82dd0d2a9a76fc8fa2b18d80b987d455728bf83a ]

Miguel reported an skb use after free / double free in vrf_finish_output when neigh_output returns an error. The vrf driver should return after the call to neigh_output as it takes over the skb on error path as well.

Patch is a simplified version of Miguel's patch which was written for 4.9, and updated to top of tree.

Fixes 8f58336d3f78a ("net: Add ethernet header for pass through VRF device")
Signed-off-by Miguel Fadon Perlines <[email protected]>
Signed-off-by David Ahern <[email protected]>
Signed-off-by David S. Miller <[email protected]>

[ backport to 4.4 and 4.9 dropped the sock_confirm_neigh and
changed neigh_output to dst_neigh_output ]
---
note to stable: this patch applies to both 4.9 and 4.4 (the latter has an offset but still applies cleanly

 drivers/net/vrf.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)
drivers/net/vrf.c +5 -3
index 346e48698555..42c9480acdc7 100644
@@ -585,13 +585,15 @@ static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *s
 	neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
 	if (unlikely(!neigh))
 		neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
-	if (!IS_ERR(neigh))
+	if (!IS_ERR(neigh)) {
 		ret = dst_neigh_output(dst, neigh, skb);
+		rcu_read_unlock_bh();
+		return ret;
+	}
 
 	rcu_read_unlock_bh();
 err:
-	if (unlikely(ret < 0))
-		vrf_tx_error(skb->dev, skb);
+	vrf_tx_error(skb->dev, skb);
 	return ret;
 }
Signature · 1 line
2.11.0
maintainer
#2 lore raw

Re: [PATCH] vrf: Fix use after free and double free in vrf_finish_output

From: David Ahern <[email protected]>
Date: Wed, 11 Apr 2018 08:10:03 -0700

Quoted 13 lines

[ upstream commit 82dd0d2a9a76fc8fa2b18d80b987d455728bf83a ]

Miguel reported an skb use after free / double free in vrf_finish_output when neigh_output returns an error. The vrf driver should return after the call to neigh_output as it takes over the skb on error path as well.

Patch is a simplified version of Miguel's patch which was written for 4.9, and updated to top of tree.

Fixes 8f58336d3f78a ("net: Add ethernet header for pass through VRF device")
Signed-off-by Miguel Fadon Perlines <[email protected]>
Signed-off-by David Ahern <[email protected]>
Signed-off-by David S. Miller <[email protected]>
Quoted 5 lines

[ backport to 4.4 and 4.9 dropped the sock_confirm_neigh and
changed neigh_output to dst_neigh_output ]
---
note to stable: this patch applies to both 4.9 and 4.4 (the latter has an offset but still applies cleanly

Stable folks, please queue this up.

#3 lore raw

Re: [PATCH] vrf: Fix use after free and double free in vrf_finish_output

Quoted 22 lines · David Miller

From: David Ahern <[email protected]>
Date: Wed, 11 Apr 2018 08:10:03 -0700

Quoted 13 lines

[ upstream commit 82dd0d2a9a76fc8fa2b18d80b987d455728bf83a ]

Miguel reported an skb use after free / double free in vrf_finish_output when neigh_output returns an error. The vrf driver should return after the call to neigh_output as it takes over the skb on error path as well.

Patch is a simplified version of Miguel's patch which was written for 4.9, and updated to top of tree.

Fixes 8f58336d3f78a ("net: Add ethernet header for pass through VRF device")
Signed-off-by Miguel Fadon Perlines <[email protected]>
Signed-off-by David Ahern <[email protected]>
Signed-off-by David S. Miller <[email protected]>
Quoted 5 lines

[ backport to 4.4 and 4.9 dropped the sock_confirm_neigh and
changed neigh_output to dst_neigh_output ]
---
note to stable: this patch applies to both 4.9 and 4.4 (the latter has an offset but still applies cleanly

Quoted 1 line

Stable folks, please queue this up.

Now applied, thanks!

greg k-h