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author | Jeremy Cline <jeremy@jcline.org> | 2017-12-14 09:50:53 -0500 |
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committer | Jeremy Cline <jeremy@jcline.org> | 2017-12-14 09:50:53 -0500 |
commit | b6e3b19cd5c54902789574a3def1787d2c143246 (patch) | |
tree | a376a89a88c6f1d98803cd69ab939fc9089904ca /netfilter-xt_osf-Add-missing-permission-checks.patch | |
parent | aede7982b7100e8b769edff793649a9b8258348d (diff) | |
download | kernel-b6e3b19cd5c54902789574a3def1787d2c143246.tar.gz kernel-b6e3b19cd5c54902789574a3def1787d2c143246.tar.xz kernel-b6e3b19cd5c54902789574a3def1787d2c143246.zip |
Linux v4.14.5
Also fixes CVE-2017-17448, CVE-2017-17449, CVE-2017-17450
Diffstat (limited to 'netfilter-xt_osf-Add-missing-permission-checks.patch')
-rw-r--r-- | netfilter-xt_osf-Add-missing-permission-checks.patch | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/netfilter-xt_osf-Add-missing-permission-checks.patch b/netfilter-xt_osf-Add-missing-permission-checks.patch new file mode 100644 index 000000000..80cd60847 --- /dev/null +++ b/netfilter-xt_osf-Add-missing-permission-checks.patch @@ -0,0 +1,59 @@ +From 2af0d441c8b1151a5d8bb46ec9c58ab575fe7d6f Mon Sep 17 00:00:00 2001 +From: Kevin Cernekee <cernekee@chromium.org> +Date: Tue, 5 Dec 2017 15:42:41 -0800 +Subject: [PATCH] netfilter: xt_osf: Add missing permission checks + +The capability check in nfnetlink_rcv() verifies that the caller +has CAP_NET_ADMIN in the namespace that "owns" the netlink socket. +However, xt_osf_fingers is shared by all net namespaces on the +system. An unprivileged user can create user and net namespaces +in which he holds CAP_NET_ADMIN to bypass the netlink_net_capable() +check: + + vpnns -- nfnl_osf -f /tmp/pf.os + + vpnns -- nfnl_osf -f /tmp/pf.os -d + +These non-root operations successfully modify the systemwide OS +fingerprint list. Add new capable() checks so that they can't. + +Signed-off-by: Kevin Cernekee <cernekee@chromium.org> +--- + net/netfilter/xt_osf.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c +index 36e14b1f061d..a34f314a8c23 100644 +--- a/net/netfilter/xt_osf.c ++++ b/net/netfilter/xt_osf.c +@@ -19,6 +19,7 @@ + #include <linux/module.h> + #include <linux/kernel.h> + ++#include <linux/capability.h> + #include <linux/if.h> + #include <linux/inetdevice.h> + #include <linux/ip.h> +@@ -70,6 +71,9 @@ static int xt_osf_add_callback(struct net *net, struct sock *ctnl, + struct xt_osf_finger *kf = NULL, *sf; + int err = 0; + ++ if (!capable(CAP_NET_ADMIN)) ++ return -EPERM; ++ + if (!osf_attrs[OSF_ATTR_FINGER]) + return -EINVAL; + +@@ -115,6 +119,9 @@ static int xt_osf_remove_callback(struct net *net, struct sock *ctnl, + struct xt_osf_finger *sf; + int err = -ENOENT; + ++ if (!capable(CAP_NET_ADMIN)) ++ return -EPERM; ++ + if (!osf_attrs[OSF_ATTR_FINGER]) + return -EINVAL; + +-- +2.14.3 + |