From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D893F136E09; Mon, 6 Jan 2025 15:44:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736178291; cv=none; b=bfnwGMcQaAvPrXUfYZDlwhKh1jnnY3iTbR0pUkjr+6EhR6yspnjiRc8WKuyDEsbJTyMsQpfZxz+bCIyW3jfPdbGwILH7g5JVkr21iGjlc+rDYbTRdeLzMbWQjJIIeB6fRGBJjnoPr/Xd8ueSiZriC++5u9aPm5wKSns/KOCdytY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736178291; c=relaxed/simple; bh=esrx66XwJPgQGXZQYm5yBIfuzesJ+F+cnN2EwnobCUQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gg+kMuBKRDkfEQY3to3y5bYv+AwKnXb6g0AIO0obY7vf//79c4hKGN2TKSrfhO+UnPbpNmtwL/jpdcrMTYOJlUXbns84Qxc7w0jysaW3vKo9b0M1+MvQwqHjfHFxjj2Zcar9SxPhelTVtqVL4AL745gmqot+H0FKfkof7Rlie/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nnZ2k6US; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nnZ2k6US" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5EEF4C4CED2; Mon, 6 Jan 2025 15:44:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736178291; bh=esrx66XwJPgQGXZQYm5yBIfuzesJ+F+cnN2EwnobCUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nnZ2k6USBWnJkwm0aD/IfOrsRdB7L166Dz4Tgxxev9pE4I0bhJ6Ivyws6XyBQeSA1 QWF16h03HWqnDUAVVjePqZz7mbZecVKiqb+pGOXYAy6ZHAB4B3c7rjD5H2A8y820uO cac2mKzVEg7D8T3ACbD8xH8bTfp/FNlNwTvZzDZU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vasily Averin , "David S. Miller" , Harshvardhan Jha , Sasha Levin Subject: [PATCH 5.10 070/138] ipv6: use skb_expand_head in ip6_finish_output2 Date: Mon, 6 Jan 2025 16:16:34 +0100 Message-ID: <20250106151135.884079257@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250106151133.209718681@linuxfoundation.org> References: <20250106151133.209718681@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vasily Averin [ Upstream commit e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2 ] Unlike skb_realloc_headroom, new helper skb_expand_head does not allocate a new skb if possible. Additionally this patch replaces commonly used dereferencing with variables. Signed-off-by: Vasily Averin Signed-off-by: David S. Miller (cherry picked from commit e415ed3a4b8b246ee5e9d109ff5153efcf96b9f2) Signed-off-by: Harshvardhan Jha Signed-off-by: Sasha Levin --- net/ipv6/ip6_output.c | 51 ++++++++++++++----------------------------- 1 file changed, 16 insertions(+), 35 deletions(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 26d8105981e9..7806963b4539 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -60,46 +60,29 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * { struct dst_entry *dst = skb_dst(skb); struct net_device *dev = dst->dev; + struct inet6_dev *idev = ip6_dst_idev(dst); unsigned int hh_len = LL_RESERVED_SPACE(dev); - int delta = hh_len - skb_headroom(skb); - const struct in6_addr *nexthop; + const struct in6_addr *daddr, *nexthop; + struct ipv6hdr *hdr; struct neighbour *neigh; int ret; /* Be paranoid, rather than too clever. */ - if (unlikely(delta > 0) && dev->header_ops) { - /* pskb_expand_head() might crash, if skb is shared */ - if (skb_shared(skb)) { - struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); - - if (likely(nskb)) { - if (skb->sk) - skb_set_owner_w(nskb, skb->sk); - consume_skb(skb); - } else { - kfree_skb(skb); - } - skb = nskb; - } - if (skb && - pskb_expand_head(skb, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) { - kfree_skb(skb); - skb = NULL; - } + if (unlikely(hh_len > skb_headroom(skb)) && dev->header_ops) { + skb = skb_expand_head(skb, hh_len); if (!skb) { - IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); + IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); return -ENOMEM; } } - if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { - struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); - + hdr = ipv6_hdr(skb); + daddr = &hdr->daddr; + if (ipv6_addr_is_multicast(daddr)) { if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && ((mroute6_is_socket(net, skb) && !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || - ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, - &ipv6_hdr(skb)->saddr))) { + ipv6_chk_mcast_addr(dev, daddr, &hdr->saddr))) { struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); /* Do not check for IFF_ALLMULTI; multicast routing @@ -110,7 +93,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * net, sk, newskb, NULL, newskb->dev, dev_loopback_xmit); - if (ipv6_hdr(skb)->hop_limit == 0) { + if (hdr->hop_limit == 0) { IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); kfree_skb(skb); @@ -119,9 +102,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * } IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len); - - if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <= - IPV6_ADDR_SCOPE_NODELOCAL && + if (IPV6_ADDR_MC_SCOPE(daddr) <= IPV6_ADDR_SCOPE_NODELOCAL && !(dev->flags & IFF_LOOPBACK)) { kfree_skb(skb); return 0; @@ -136,10 +117,10 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * } rcu_read_lock_bh(); - nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); - neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); + nexthop = rt6_nexthop((struct rt6_info *)dst, daddr); + neigh = __ipv6_neigh_lookup_noref(dev, nexthop); if (unlikely(!neigh)) - neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); + neigh = __neigh_create(&nd_tbl, nexthop, dev, false); if (!IS_ERR(neigh)) { sock_confirm_neigh(skb, neigh); ret = neigh_output(neigh, skb, false); @@ -148,7 +129,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * } rcu_read_unlock_bh(); - IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); + IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES); kfree_skb(skb); return -EINVAL; } -- 2.39.5