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From: Steffen Klassert <steffen.klassert@secunet.com>
To: David Miller <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	Steffen Klassert <steffen.klassert@secunet.com>,
	<netdev@vger.kernel.org>
Subject: [PATCH 2/7] esp: Fix locking on page fragment allocation
Date: Tue, 29 Aug 2017 12:31:29 +0200	[thread overview]
Message-ID: <1504002694-1931-3-git-send-email-steffen.klassert@secunet.com> (raw)
In-Reply-To: <1504002694-1931-1-git-send-email-steffen.klassert@secunet.com>

We allocate the page fragment for the ESP trailer inside
a spinlock, but consume it outside of the lock. This
is racy as some other cou could get the same page fragment
then. Fix this by consuming the page fragment inside the
lock too.

Fixes: cac2661c53f3 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a27 ("esp6: Avoid skb_cow_data whenever possible")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv4/esp4.c | 5 +++--
 net/ipv6/esp6.c | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index dbb31a9..a8ddb95 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -292,8 +292,6 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
 
 			kunmap_atomic(vaddr);
 
-			spin_unlock_bh(&x->lock);
-
 			nfrags = skb_shinfo(skb)->nr_frags;
 
 			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
@@ -301,6 +299,9 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
 			skb_shinfo(skb)->nr_frags = ++nfrags;
 
 			pfrag->offset = pfrag->offset + allocsize;
+
+			spin_unlock_bh(&x->lock);
+
 			nfrags++;
 
 			skb->len += tailen;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 392def1..4e3fdc88 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -260,8 +260,6 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
 
 			kunmap_atomic(vaddr);
 
-			spin_unlock_bh(&x->lock);
-
 			nfrags = skb_shinfo(skb)->nr_frags;
 
 			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
@@ -269,6 +267,9 @@ int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info
 			skb_shinfo(skb)->nr_frags = ++nfrags;
 
 			pfrag->offset = pfrag->offset + allocsize;
+
+			spin_unlock_bh(&x->lock);
+
 			nfrags++;
 
 			skb->len += tailen;
-- 
2.7.4

  parent reply	other threads:[~2017-08-29 10:31 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-29 10:31 pull request (net): ipsec 2017-08-29 Steffen Klassert
2017-08-29 10:31 ` [PATCH 1/7] net: xfrm: don't double-hold dst when sk_policy in use Steffen Klassert
2017-08-29 10:31 ` Steffen Klassert [this message]
2017-08-29 10:31 ` [PATCH 3/7] esp: Fix skb tailroom calculation Steffen Klassert
2017-08-29 10:31 ` [PATCH 4/7] xfrm_user: fix info leak in copy_user_offload() Steffen Klassert
2017-08-29 10:31 ` [PATCH 5/7] xfrm_user: fix info leak in xfrm_notify_sa() Steffen Klassert
2017-08-29 10:31 ` [PATCH 6/7] xfrm_user: fix info leak in build_expire() Steffen Klassert
2017-08-29 10:31 ` [PATCH 7/7] xfrm_user: fix info leak in build_aevent() Steffen Klassert
2017-08-29 16:37 ` pull request (net): ipsec 2017-08-29 David Miller

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