commit: b8d213a1983935e8741527f7a87ff63f1a44e648 Author: Mike Pagano <mpagano <AT> gentoo <DOT> org> AuthorDate: Fri Apr 14 19:17:28 2017 +0000 Commit: Mike Pagano <mpagano <AT> gentoo <DOT> org> CommitDate: Fri Apr 14 19:17:28 2017 +0000 URL: https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=b8d213a1
Fix for CVE-2016-10229. Unsafe second checksum calculation in udp.c. See bug #615480. 0000_README | 4 + ...udp-prop-suprt-MSG-PEEK-wth-trunc-buffers.patch | 94 ++++++++++++++++++++++ 2 files changed, 98 insertions(+) diff --git a/0000_README b/0000_README index 80a401b..c91ff69 100644 --- a/0000_README +++ b/0000_README @@ -211,6 +211,10 @@ Patch: 1520_CVE-2017-6074-dccp-skb-freeing-fix.patch From: https://bugs.gentoo.org/show_bug.cgi?id=610600 Desc: dccp: fix freeing skb too early for IPV6_RECVPKTINFO. CVE-2017-6074 +Patch: 1530_udp-prop-suprt-MSG-PEEK-wth-trunc-buffers.patch +From: https://bugs.gentoo.org/show_bug.cgi?id=615480 +Desc: Fixes CVE-2016-10229. Unsafe second checksum calculation in udp.c + Patch: 1800_fix-lru-cache-add-oom-regression.patch From: http://thread.gmane.org/gmane.linux.kernel.stable/184384 Desc: Revert commit 8f182270dfec mm/swap.c: flush lru pvecs on compound page arrival to fix OOM error. diff --git a/1530_udp-prop-suprt-MSG-PEEK-wth-trunc-buffers.patch b/1530_udp-prop-suprt-MSG-PEEK-wth-trunc-buffers.patch new file mode 100644 index 0000000..1d12eaa --- /dev/null +++ b/1530_udp-prop-suprt-MSG-PEEK-wth-trunc-buffers.patch @@ -0,0 +1,94 @@ +From 197c949e7798fbf28cfadc69d9ca0c2abbf93191 Mon Sep 17 00:00:00 2001 +From: Eric Dumazet <eduma...@google.com> +Date: Wed, 30 Dec 2015 08:51:12 -0500 +Subject: udp: properly support MSG_PEEK with truncated buffers + +Backport of this upstream commit into stable kernels : +89c22d8c3b27 ("net: Fix skb csum races when peeking") +exposed a bug in udp stack vs MSG_PEEK support, when user provides +a buffer smaller than skb payload. + +In this case, +skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), + msg->msg_iov); +returns -EFAULT. + +This bug does not happen in upstream kernels since Al Viro did a great +job to replace this into : +skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg); +This variant is safe vs short buffers. + +For the time being, instead reverting Herbert Xu patch and add back +skb->ip_summed invalid changes, simply store the result of +udp_lib_checksum_complete() so that we avoid computing the checksum a +second time, and avoid the problematic +skb_copy_and_csum_datagram_iovec() call. + +This patch can be applied on recent kernels as it avoids a double +checksumming, then backported to stable kernels as a bug fix. + +Signed-off-by: Eric Dumazet <eduma...@google.com> +Acked-by: Herbert Xu <herb...@gondor.apana.org.au> +Signed-off-by: David S. Miller <da...@davemloft.net> +--- + net/ipv4/udp.c | 6 ++++-- + net/ipv6/udp.c | 6 ++++-- + 2 files changed, 8 insertions(+), 4 deletions(-) + +diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c +index 8841e98..ac14ae4 100644 +--- a/net/ipv4/udp.c ++++ b/net/ipv4/udp.c +@@ -1271,6 +1271,7 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, + int peeked, off = 0; + int err; + int is_udplite = IS_UDPLITE(sk); ++ bool checksum_valid = false; + bool slow; + + if (flags & MSG_ERRQUEUE) +@@ -1296,11 +1297,12 @@ try_again: + */ + + if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { +- if (udp_lib_checksum_complete(skb)) ++ checksum_valid = !udp_lib_checksum_complete(skb); ++ if (!checksum_valid) + goto csum_copy_err; + } + +- if (skb_csum_unnecessary(skb)) ++ if (checksum_valid || skb_csum_unnecessary(skb)) + err = skb_copy_datagram_msg(skb, sizeof(struct udphdr), + msg, copied); + else { +diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c +index 9da3287..00775ee 100644 +--- a/net/ipv6/udp.c ++++ b/net/ipv6/udp.c +@@ -402,6 +402,7 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int peeked, off = 0; + int err; + int is_udplite = IS_UDPLITE(sk); ++ bool checksum_valid = false; + int is_udp4; + bool slow; + +@@ -433,11 +434,12 @@ try_again: + */ + + if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { +- if (udp_lib_checksum_complete(skb)) ++ checksum_valid = !udp_lib_checksum_complete(skb); ++ if (!checksum_valid) + goto csum_copy_err; + } + +- if (skb_csum_unnecessary(skb)) ++ if (checksum_valid || skb_csum_unnecessary(skb)) + err = skb_copy_datagram_msg(skb, sizeof(struct udphdr), + msg, copied); + else { +-- +cgit v1.1 +
