From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35806 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753618AbbIZSlm (ORCPT ); Sat, 26 Sep 2015 14:41:42 -0400 Subject: Patch "net: Fix skb_set_peeked use-after-free bug" has been added to the 4.1-stable tree To: herbert@gondor.apana.org.au, bblanco@plumgrid.com, davem@davemloft.net, gregkh@linuxfoundation.org, khlebnikov@yandex-team.ru Cc: , From: Date: Sat, 26 Sep 2015 11:41:41 -0700 Message-ID: <14432929015227@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled net: Fix skb_set_peeked use-after-free bug to the 4.1-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: net-fix-skb_set_peeked-use-after-free-bug.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Sat Sep 26 11:13:07 PDT 2015 From: Herbert Xu Date: Tue, 4 Aug 2015 15:42:47 +0800 Subject: net: Fix skb_set_peeked use-after-free bug From: Herbert Xu [ Upstream commit a0a2a6602496a45ae838a96db8b8173794b5d398 ] The commit 738ac1ebb96d02e0d23bc320302a6ea94c612dec ("net: Clone skb before setting peeked flag") introduced a use-after-free bug in skb_recv_datagram. This is because skb_set_peeked may create a new skb and free the existing one. As it stands the caller will continue to use the old freed skb. This patch fixes it by making skb_set_peeked return the new skb (or the old one if unchanged). Fixes: 738ac1ebb96d ("net: Clone skb before setting peeked flag") Reported-by: Brenden Blanco Signed-off-by: Herbert Xu Tested-by: Brenden Blanco Reviewed-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/datagram.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -131,12 +131,12 @@ out_noerr: goto out; } -static int skb_set_peeked(struct sk_buff *skb) +static struct sk_buff *skb_set_peeked(struct sk_buff *skb) { struct sk_buff *nskb; if (skb->peeked) - return 0; + return skb; /* We have to unshare an skb before modifying it. */ if (!skb_shared(skb)) @@ -144,7 +144,7 @@ static int skb_set_peeked(struct sk_buff nskb = skb_clone(skb, GFP_ATOMIC); if (!nskb) - return -ENOMEM; + return ERR_PTR(-ENOMEM); skb->prev->next = nskb; skb->next->prev = nskb; @@ -157,7 +157,7 @@ static int skb_set_peeked(struct sk_buff done: skb->peeked = 1; - return 0; + return skb; } /** @@ -229,8 +229,9 @@ struct sk_buff *__skb_recv_datagram(stru continue; } - error = skb_set_peeked(skb); - if (error) + skb = skb_set_peeked(skb); + error = PTR_ERR(skb); + if (IS_ERR(skb)) goto unlock_err; atomic_inc(&skb->users); Patches currently in stable-queue which might be from herbert@gondor.apana.org.au are queue-4.1/powerpc-uncomment-and-make-enable_kernel_vsx-routine-available.patch queue-4.1/net-fix-skb_set_peeked-use-after-free-bug.patch queue-4.1/ipv6-lock-socket-in-ip6_datagram_connect.patch queue-4.1/net-fix-skb-csum-races-when-peeking.patch queue-4.1/rhashtable-fix-for-resize-events-during-table-walk.patch queue-4.1/net-clone-skb-before-setting-peeked-flag.patch queue-4.1/revert-sit-add-gro-callbacks-to-sit_offload.patch queue-4.1/crypto-vmx-adding-enable_kernel_vsx-to-access-vsx-instructions.patch queue-4.1/netlink-make-sure-ebusy-won-t-escape-from-netlink_insert.patch