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| author | Justin M. Forbes <jforbes@redhat.com> | 2017-02-13 08:58:32 -0600 |
|---|---|---|
| committer | Justin M. Forbes <jforbes@redhat.com> | 2017-02-13 08:58:32 -0600 |
| commit | 587708b82a8b7dda59c0b86ae91f6618769fe4c0 (patch) | |
| tree | fe56f5e4fe8f2baddb5e96e829e52a2bf3918286 | |
| parent | 75d1ad4d4b73e05817151d98499af7e6e9f39183 (diff) | |
| download | kernel-587708b82a8b7dda59c0b86ae91f6618769fe4c0.tar.gz kernel-587708b82a8b7dda59c0b86ae91f6618769fe4c0.tar.xz kernel-587708b82a8b7dda59c0b86ae91f6618769fe4c0.zip | |
CVE-2017-5970 keep skb->dst around in presence of IP options (rhbz 1421638)
| -rw-r--r-- | ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch | 47 | ||||
| -rw-r--r-- | kernel.spec | 6 |
2 files changed, 53 insertions, 0 deletions
diff --git a/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch b/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch new file mode 100644 index 000000000..821e3fce8 --- /dev/null +++ b/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch @@ -0,0 +1,47 @@ +From 34b2cef20f19c87999fff3da4071e66937db9644 Mon Sep 17 00:00:00 2001 +From: Eric Dumazet <edumazet@google.com> +Date: Sat, 4 Feb 2017 11:16:52 -0800 +Subject: [PATCH] ipv4: keep skb->dst around in presence of IP options + +Andrey Konovalov got crashes in __ip_options_echo() when a NULL skb->dst +is accessed. + +ipv4_pktinfo_prepare() should not drop the dst if (evil) IP options +are present. + +We could refine the test to the presence of ts_needtime or srr, +but IP options are not often used, so let's be conservative. + +Thanks to syzkaller team for finding this bug. + +Fixes: d826eb14ecef ("ipv4: PKTINFO doesnt need dst reference") +Signed-off-by: Eric Dumazet <edumazet@google.com> +Reported-by: Andrey Konovalov <andreyknvl@google.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + net/ipv4/ip_sockglue.c | 9 ++++++++- + 1 file changed, 8 insertions(+), 1 deletion(-) + +diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c +index 53ae0c6..9000117 100644 +--- a/net/ipv4/ip_sockglue.c ++++ b/net/ipv4/ip_sockglue.c +@@ -1238,7 +1238,14 @@ void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb) + pktinfo->ipi_ifindex = 0; + pktinfo->ipi_spec_dst.s_addr = 0; + } +- skb_dst_drop(skb); ++ /* We need to keep the dst for __ip_options_echo() ++ * We could restrict the test to opt.ts_needtime || opt.srr, ++ * but the following is good enough as IP options are not often used. ++ */ ++ if (unlikely(IPCB(skb)->opt.optlen)) ++ skb_dst_force(skb); ++ else ++ skb_dst_drop(skb); + } + + int ip_setsockopt(struct sock *sk, int level, +-- +2.9.3 + diff --git a/kernel.spec b/kernel.spec index dee7635a4..966d0ecc9 100644 --- a/kernel.spec +++ b/kernel.spec @@ -649,6 +649,9 @@ Patch860: 0001-sctp-avoid-BUG_ON-on-sctp_wait_for_sndbuf.patch #rhbz 1415397 Patch861: w1-ds2490-USB-transfer-buffers-need-to-be-DMAable.patch +#CVE-2017-5970 rhbz 1421638 +Patch862: ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch + # END OF PATCH DEFINITIONS %endif @@ -2178,6 +2181,9 @@ fi # # %changelog +* Mon Feb 13 2017 Justin M. Forbes <jforbes@fedoraproject.org> +- CVE-2017-5970 keep skb->dst around in presence of IP options (rhbz 1421638) + * Thu Feb 9 2017 Peter Robinson <pbrobinson@fedoraproject.org> - Fix OOPSes in vc4 (Raspberry Pi) |