From 1155493454bf1e013f5b086ba7529c1cd60fd242 Mon Sep 17 00:00:00 2001 From: Carmelo Amoroso Date: Fri, 14 Oct 2011 12:04:58 +0200 Subject: ldd: take LD_LIBRARY_PATH into account 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 Signed-off-by: Carmelo Amoroso --- utils/Makefile.in | 2 +- utils/ldd.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 49 insertions(+), 3 deletions(-) (limited to 'utils') diff --git a/utils/Makefile.in b/utils/Makefile.in index 65364d771..b634b81e5 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 6d08efd54..c56ddc8d5 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; } -- cgit v1.2.3