From ffe48a81783cc07e2f12e158e5b3985d1f313c9b Mon Sep 17 00:00:00 2001

Message-Id: <ffe48a81783cc07e2f12e158e5b3985d1f313c9b.1383321464.git.jdenemar@redhat.com>

From: "Daniel P. Berrange" <berrange@redhat.com>

Date: Wed, 30 Oct 2013 17:01:41 +0000

Subject: [PATCH] Add helpers for getting env vars in a setuid environment

For

  https://bugzilla.redhat.com/show_bug.cgi?id=1015247

Care must be taken accessing env variables when running

setuid. Introduce a virGetEnvAllowSUID for env vars which

are safe to use in a setuid environment, and another

virGetEnvBlockSUID for vars which are not safe. Also add

a virIsSUID helper method for any other non-env var code

to use.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

(cherry picked from commit ae53e5d10e434e07079d7e3ba11ec654ba6a256e)

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 bootstrap.conf           |  1 +

 src/libvirt_private.syms |  3 +++

 src/util/virutil.c       | 39 +++++++++++++++++++++++++++++++++++++++

 src/util/virutil.h       |  4 ++++

 4 files changed, 47 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms

index f96f126..374a332 100644

--- a/src/libvirt_private.syms

+++ b/src/libvirt_private.syms

@@ -2046,6 +2046,8 @@ virFindFCHostCapableVport;

 virFormatIntDecimal;

 virGetDeviceID;

 virGetDeviceUnprivSGIO;

+virGetEnvAllowSUID;

+virGetEnvBlockSUID;

 virGetFCHostNameByWWN;

 virGetGroupID;

 virGetGroupList;

@@ -2064,6 +2066,7 @@ virIndexToDiskName;

 virIsCapableFCHost;

 virIsCapableVport;

 virIsDevMapperDevice;

+virIsSUID;

 virManageVport;

 virParseNumber;

 virParseOwnershipIds;

diff --git a/src/util/virutil.c b/src/util/virutil.c

index 3abcd53..a41117e 100644

--- a/src/util/virutil.c

+++ b/src/util/virutil.c

@@ -2096,3 +2096,42 @@ cleanup:

     return rc;

 }

+

+

+/**

+ * virGetEnvBlockSUID:

+ * @name: the environment variable name

+ *

+ * Obtain an environment variable which is unsafe to

+ * use when running setuid. If running setuid, a NULL

+ * value will be returned

+ */

+const char *virGetEnvBlockSUID(const char *name)

+{

+    return secure_getenv(name);

+}

+

+

+/**

+ * virGetEnvBlockSUID:

+ * @name: the environment variable name

+ *

+ * Obtain an environment variable which is safe to

+ * use when running setuid. The value will be returned

+ * even when running setuid

+ */

+const char *virGetEnvAllowSUID(const char *name)

+{

+    return getenv(name);

+}

+

+

+/**

+ * virIsSUID:

+ * Return a true value if running setuid. Does not

+ * check for elevated capabilities bits.

+ */

+bool virIsSUID(void)

+{

+    return getuid() != geteuid();

+}

diff --git a/src/util/virutil.h b/src/util/virutil.h

index 4b06992..8739e4e 100644

--- a/src/util/virutil.h

+++ b/src/util/virutil.h

@@ -172,4 +172,8 @@ int virCompareLimitUlong(unsigned long long a, unsigned long b);

 int virParseOwnershipIds(const char *label, uid_t *uidPtr, gid_t *gidPtr);

+const char *virGetEnvBlockSUID(const char *name);

+const char *virGetEnvAllowSUID(const char *name);

+bool virIsSUID(void);

+

 #endif /* __VIR_UTIL_H__ */

-- 

1.8.4.2