diff --git a/debian/changelog b/debian/changelog index 4a066b0f2..7221d92c4 100644 --- a/debian/changelog +++ b/debian/changelog @@ -197,6 +197,7 @@ linux (4.9.9-1) UNRELEASED; urgency=medium [ Salvatore Bonaccorso ] * IB/rxe: Fix mem_check_range integer overflow (CVE-2016-8636) * selinux: fix off-by-one in setprocattr (CVE-2017-2618) + * ipv4: keep skb->dst around in presence of IP options (CVE-2017-5970) -- Ben Hutchings Fri, 27 Jan 2017 18:14:31 +0000 diff --git a/debian/patches/bugfix/all/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch b/debian/patches/bugfix/all/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch new file mode 100644 index 000000000..cb1c8ad2b --- /dev/null +++ b/debian/patches/bugfix/all/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch @@ -0,0 +1,47 @@ +From: Eric Dumazet +Date: Sat, 4 Feb 2017 11:16:52 -0800 +Subject: ipv4: keep skb->dst around in presence of IP options +Origin: https://git.kernel.org/linus/34b2cef20f19c87999fff3da4071e66937db9644 + +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 +Reported-by: Andrey Konovalov +Signed-off-by: David S. Miller +--- + 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, +-- +2.1.4 + diff --git a/debian/patches/series b/debian/patches/series index dfab2f599..cbd1721ac 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -106,6 +106,7 @@ features/all/securelevel/arm64-add-kernel-config-option-to-set-securelevel-wh.pa debian/i386-686-pae-pci-set-pci-nobios-by-default.patch bugfix/all/IB-rxe-Fix-mem_check_range-integer-overflow.patch bugfix/all/selinux-fix-off-by-one-in-setprocattr.patch +bugfix/all/ipv4-keep-skb-dst-around-in-presence-of-IP-options.patch # Fix exported symbol versions bugfix/ia64/revert-ia64-move-exports-to-definitions.patch