[git commit] ldd: take LD_LIBRARY_PATH into account
Carmelo Amoroso
carmelo.amoroso at st.com
Tue Oct 18 09:23:55 UTC 2011
commit: http://git.uclibc.org/uClibc/commit/?id=1155493454bf1e013f5b086ba7529c1cd60fd242
branch: http://git.uclibc.org/uClibc/commit/?id=refs/heads/master
Extend the environment variables adding the LD_LIBRARY_PATH
if actually passed when doing shared library tracings through
the ld.so trace capability.
This is possible only using the system dynamic linker in stand-alone
mode to avoid any vulnerability.
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop at gmail.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso at st.com>
---
utils/Makefile.in | 2 +-
utils/ldd.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 49 insertions(+), 3 deletions(-)
diff --git a/utils/Makefile.in b/utils/Makefile.in
index 65364d7..b634b81 100644
--- a/utils/Makefile.in
+++ b/utils/Makefile.in
@@ -12,7 +12,7 @@ CFLAGS-utils := \
$(SSP_ALL_CFLAGS) \
-I$(top_srcdir)ldso/include \
-DUCLIBC_RUNTIME_PREFIX=\"$(RUNTIME_PREFIX)\" \
- -DUCLIBC_LDSO=$(UCLIBC_LDSO) \
+ -DUCLIBC_LDSO=\"$(UCLIBC_LDSO)\" \
-I$(top_srcdir)/$(KERNEL_HEADERS) \
-DNOT_IN_libc \
-B$(top_builddir)lib \
diff --git a/utils/ldd.c b/utils/ldd.c
index 6d08efd..c56ddc8 100644
--- a/utils/ldd.c
+++ b/utils/ldd.c
@@ -127,6 +127,9 @@
#define ELFDATAM ELFDATA2MSB
#endif
+#define ARRAY_SIZE(v) (sizeof(v) / sizeof(*v))
+#define TRUSTED_LDSO UCLIBC_RUNTIME_PREFIX "lib/" UCLIBC_LDSO
+
struct library {
char *name;
int resolved;
@@ -698,16 +701,59 @@ foo:
"LD_TRACE_LOADED_OBJECTS=1",
NULL
};
-
+ char * lib_path = getenv("LD_LIBRARY_PATH");
+
+#ifdef __LDSO_STANDALONE_SUPPORT__
+ /* The 'extended' environment inclusing the LD_LIBRARY_PATH */
+ static char *ext_environment[ARRAY_SIZE(environment) + 1];
+ char **envp = (char **) environment;
+
+ if (lib_path) {
+ /*
+ * If the LD_LIBRARY_PATH is set, it needs to include it
+ * into the environment for the new process to be spawned
+ */
+ char ** eenvp = (char **) ext_environment;
+
+ /* Copy the N-1 environment's entries */
+ while (*envp)
+ *eenvp++=*envp++;
+
+ /* Make room for LD_LIBRARY_PATH */
+ *eenvp = (char *) malloc(sizeof("LD_LIBRARY_PATH=")
+ + strlen(lib_path));
+ strcpy(*eenvp, "LD_LIBRARY_PATH=");
+ strcat(*eenvp, lib_path);
+ lib_path = *eenvp;
+ /* ext_environment[size] is already NULL */
+
+ /* Use the extended environment */
+ envp = ext_environment;
+ }
+ if ((pid = vfork()) == 0) {
+ /*
+ * Force to use the standard dynamic linker in stand-alone mode.
+ * It will fails at runtime if support is not actually available
+ */
+ execle(TRUSTED_LDSO, TRUSTED_LDSO, filename, NULL, envp);
+ _exit(0xdead);
+ }
+#else
if ((pid = vfork()) == 0) {
/* Cool, it looks like we should be able to actually
* run this puppy. Do so now... */
execle(filename, filename, NULL, environment);
_exit(0xdead);
}
-
+#endif
/* Wait till it returns */
waitpid(pid, &status, 0);
+
+#ifdef __LDSO_STANDALONE_SUPPORT__
+ /* Do not leak */
+ free(lib_path);
+#endif
+
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
return 1;
}
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