# http://seclists.org/fulldisclosure/2010/Oct/257 # http://sourceware.org/ml/libc-hacker/2010-10/msg00007.html Path elements containing $ORIGIN should always be ignored in privileged programs. Andreas. 2010-10-18 Andreas Schwab * elf/dl-load.c (is_dst): Remove last parameter. (_dl_dst_count): Ignore $ORIGIN in privileged programs. (_dl_dst_substitute): Likewise. --- elf/dl-load.c | 30 +++++++++++++----------------- 1 files changed, 13 insertions(+), 17 deletions(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index a7162eb..776f7e4 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -169,8 +169,7 @@ local_strdup (const char *s) static size_t -is_dst (const char *start, const char *name, const char *str, - int is_path, int secure) +is_dst (const char *start, const char *name, const char *str, int is_path) { size_t len; bool is_curly = false; @@ -199,11 +198,6 @@ is_dst (const char *start, const char *name, const char *str, && (!is_path || name[len] != ':')) return 0; - if (__builtin_expect (secure, 0) - && ((name[len] != '\0' && (!is_path || name[len] != ':')) - || (name != start + 1 && (!is_path || name[-2] != ':')))) - return 0; - return len; } @@ -218,13 +212,12 @@ _dl_dst_count (const char *name, int is_path) { size_t len; - /* $ORIGIN is not expanded for SUID/GUID programs (except if it - is $ORIGIN alone) and it must always appear first in path. */ + /* $ORIGIN is not expanded for SUID/GUID programs. */ ++name; - if ((len = is_dst (start, name, "ORIGIN", is_path, - INTUSE(__libc_enable_secure))) != 0 - || (len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0 - || (len = is_dst (start, name, "LIB", is_path, 0)) != 0) + if (((len = is_dst (start, name, "ORIGIN", is_path)) != 0 + && !INTUSE(__libc_enable_secure)) + || (len = is_dst (start, name, "PLATFORM", is_path)) != 0 + || (len = is_dst (start, name, "LIB", is_path)) != 0) ++cnt; name = strchr (name + len, '$'); @@ -256,9 +249,12 @@ _dl_dst_substitute (struct link_map *l, const char *name, char *result, size_t len; ++name; - if ((len = is_dst (start, name, "ORIGIN", is_path, - INTUSE(__libc_enable_secure))) != 0) + if ((len = is_dst (start, name, "ORIGIN", is_path)) != 0) { + /* Ignore this path element in SUID/SGID programs. */ + if (INTUSE(__libc_enable_secure)) + repl = (const char *) -1; + else #ifndef SHARED if (l == NULL) repl = _dl_get_origin (); @@ -266,9 +262,9 @@ _dl_dst_substitute (struct link_map *l, const char *name, char *result, #endif repl = l->l_origin; } - else if ((len = is_dst (start, name, "PLATFORM", is_path, 0)) != 0) + else if ((len = is_dst (start, name, "PLATFORM", is_path)) != 0) repl = GLRO(dl_platform); - else if ((len = is_dst (start, name, "LIB", is_path, 0)) != 0) + else if ((len = is_dst (start, name, "LIB", is_path)) != 0) repl = DL_DST_LIB; if (repl != NULL && repl != (const char *) -1) -- 1.7.2.3 -- Andreas Schwab, schwab@redhat.com GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84 5EC7 45C6 250E 6F00 984E "And now for something completely different."