[yocto] [meta-selinux][PATCH] libcap-ng: CVE-2014-3215
jackie.huang at windriver.com
jackie.huang at windriver.com
Tue Jul 22 23:56:36 PDT 2014
From: Shan Hai <shan.hai at windriver.com>
seunshare in policycoreutils 2.2.5 is owned by root with 4755 permissions,
and executes programs in a way that changes the relationship between the
setuid system call and the getresuid saved set-user-ID value, which makes
it easier for local users to gain privileges by leveraging a program that
mistakenly expected that it could permanently drop privileges.
Pick a patch from below link to address the CVE-2014-3215.
https://bugzilla.redhat.com/attachment.cgi?id=829864
Signed-off-by: Shan Hai <shan.hai at windriver.com>
Signed-off-by: Jackie Huang <jackie.huang at windriver.com>
---
.../libcap-ng/libcap-ng/CVE-2014-3215.patch | 79 ++++++++++++++++++++++
recipes-security/libcap-ng/libcap-ng_0.7.3.bb | 4 +-
2 files changed, 82 insertions(+), 1 deletion(-)
create mode 100644 recipes-security/libcap-ng/libcap-ng/CVE-2014-3215.patch
diff --git a/recipes-security/libcap-ng/libcap-ng/CVE-2014-3215.patch b/recipes-security/libcap-ng/libcap-ng/CVE-2014-3215.patch
new file mode 100644
index 0000000..d7a868d
--- /dev/null
+++ b/recipes-security/libcap-ng/libcap-ng/CVE-2014-3215.patch
@@ -0,0 +1,79 @@
+Upstream-Status: Pending
+
+diff --git a/docs/capng_lock.3 b/docs/capng_lock.3
+index 7683119..a070c1e 100644
+--- a/docs/capng_lock.3
++++ b/docs/capng_lock.3
+@@ -8,12 +8,13 @@ int capng_lock(void);
+
+ .SH "DESCRIPTION"
+
+-capng_lock will take steps to prevent children of the current process to regain full privileges if the uid is 0. This should be called while possessing the CAP_SETPCAP capability in the kernel. This function will do the following if permitted by the kernel: Set the NOROOT option on for PR_SET_SECUREBITS, set the NOROOT_LOCKED option to on for PR_SET_SECUREBITS, set the PR_NO_SETUID_FIXUP option on for PR_SET_SECUREBITS, and set the PR_NO_SETUID_FIXUP_LOCKED option on for PR_SET_SECUREBITS.
++capng_lock will take steps to prevent children of the current process from gaining privileges by executing setuid programs. This should be called while possessing the CAP_SETPCAP capability in the kernel.
+
++This function will do the following if permitted by the kernel: If the kernel supports PR_SET_NO_NEW_PRIVS, it will use it. Otherwise it will set the NOROOT option on for PR_SET_SECUREBITS, set the NOROOT_LOCKED option to on for PR_SET_SECUREBITS, set the PR_NO_SETUID_FIXUP option on for PR_SET_SECUREBITS, and set the PR_NO_SETUID_FIXUP_LOCKED option on for PR_SET_SECUREBITS. If both fail, it will return an error.
+
+ .SH "RETURN VALUE"
+
+-This returns 0 on success and a negative number on failure. -1 means a failure setting any of the PR_SET_SECUREBITS options.
++This returns 0 on success and a negative number on failure. -1 means a failure to use PR_SET_NO_NEW_PRIVS and a failure setting any of the PR_SET_SECUREBITS options.
+
+ .SH "SEE ALSO"
+
+diff --git a/src/cap-ng.c b/src/cap-ng.c
+index bd105ba..422f2bc 100644
+--- a/src/cap-ng.c
++++ b/src/cap-ng.c
+@@ -45,6 +45,7 @@
+ * 2.6.24 kernel XATTR_NAME_CAPS
+ * 2.6.25 kernel PR_CAPBSET_DROP, CAPABILITY_VERSION_2
+ * 2.6.26 kernel PR_SET_SECUREBITS, SECURE_*_LOCKED, VERSION_3
++ * 3.5 kernel PR_SET_NO_NEW_PRIVS
+ */
+
+ /* External syscall prototypes */
+@@ -122,6 +123,14 @@ extern int capget(cap_user_header_t header, const cap_user_data_t data);
+ #define SECURE_NO_SETUID_FIXUP_LOCKED 3 /* make bit-2 immutable */
+ #endif
+
++/* prctl values that we use */
++#ifndef PR_SET_SECUREBITS
++#define PR_SET_SECUREBITS 28
++#endif
++#ifndef PR_SET_NO_NEW_PRIVS
++#define PR_SET_NO_NEW_PRIVS 38
++#endif
++
+ // States: new, allocated, initted, updated, applied
+ typedef enum { CAPNG_NEW, CAPNG_ERROR, CAPNG_ALLOCATED, CAPNG_INIT,
+ CAPNG_UPDATED, CAPNG_APPLIED } capng_states_t;
+@@ -663,15 +672,22 @@ int capng_change_id(int uid, int gid, capng_flags_t flag)
+
+ int capng_lock(void)
+ {
+-#ifdef PR_SET_SECUREBITS
+- int rc = prctl(PR_SET_SECUREBITS,
+- 1 << SECURE_NOROOT |
+- 1 << SECURE_NOROOT_LOCKED |
+- 1 << SECURE_NO_SETUID_FIXUP |
+- 1 << SECURE_NO_SETUID_FIXUP_LOCKED, 0, 0, 0);
++ int rc;
++
++ // On Linux 3.5 and up, we can directly prevent ourselves and
++ // our descendents from gaining privileges.
++ if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == 0)
++ return 0;
++
++ // This kernel is too old or otherwise doesn't support
++ // PR_SET_NO_NEW_PRIVS. Fall back to using securebits.
++ rc = prctl(PR_SET_SECUREBITS,
++ 1 << SECURE_NOROOT |
++ 1 << SECURE_NOROOT_LOCKED |
++ 1 << SECURE_NO_SETUID_FIXUP |
++ 1 << SECURE_NO_SETUID_FIXUP_LOCKED, 0, 0, 0);
+ if (rc)
+ return -1;
+-#endif
+
+ return 0;
+ }
diff --git a/recipes-security/libcap-ng/libcap-ng_0.7.3.bb b/recipes-security/libcap-ng/libcap-ng_0.7.3.bb
index 3f225ba..e729518 100644
--- a/recipes-security/libcap-ng/libcap-ng_0.7.3.bb
+++ b/recipes-security/libcap-ng/libcap-ng_0.7.3.bb
@@ -8,7 +8,9 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=94d55d512a9ba36caa9b7df079bae19f \
file://COPYING.LIB;md5=e3eda01d9815f8d24aae2dbd89b68b06"
SRC_URI = "http://people.redhat.com/sgrubb/libcap-ng/libcap-ng-${PV}.tar.gz \
- file://python.patch"
+ file://python.patch \
+ file://CVE-2014-3215.patch \
+ "
inherit lib_package autotools pythonnative
--
2.0.0
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