diff options
Diffstat (limited to 'sysdeps/generic/dl-sysdep.c')
| -rw-r--r-- | sysdeps/generic/dl-sysdep.c | 32 |
1 files changed, 14 insertions, 18 deletions
diff --git a/sysdeps/generic/dl-sysdep.c b/sysdeps/generic/dl-sysdep.c index 0f5f0fcdab..17e8f4dcf2 100644 --- a/sysdeps/generic/dl-sysdep.c +++ b/sysdeps/generic/dl-sysdep.c @@ -79,9 +79,7 @@ _dl_sysdep_start (void **start_argptr, ElfW(Addr) user_entry; ElfW(auxv_t) *av; uid_t uid = 0; - uid_t euid = 0; gid_t gid = 0; - gid_t egid = 0; #ifdef HAVE_AUX_XID # define set_seen(tag) (tag) /* Evaluate for the side effects. */ #else @@ -117,16 +115,12 @@ _dl_sysdep_start (void **start_argptr, break; #endif case AT_UID: - uid = av->a_un.a_val; - break; - case AT_GID: - gid = av->a_un.a_val; - break; case AT_EUID: - euid = av->a_un.a_val; + uid ^= av->a_un.a_val; break; + case AT_GID: case AT_EGID: - egid = av->a_un.a_val; + gid ^= av->a_un.a_val; break; case AT_PLATFORM: GL(dl_platform) = av->a_un.a_ptr; @@ -146,18 +140,20 @@ _dl_sysdep_start (void **start_argptr, DL_SYSDEP_OSCHECK (dl_fatal); #endif - /* Linux doesn't provide us with any of these values on the stack - when the dynamic linker is run directly as a program. */ - + /* Fill in the values we have not gotten from the kernel through the + auxiliary vector. */ #ifndef HAVE_AUX_XID -# define SEE(UID, uid) if ((seen & M (AT_##UID)) == 0) uid = __get##uid () - SEE (UID, uid); - SEE (GID, gid); - SEE (EUID, euid); - SEE (EGID, egid); +# define SEE(UID, var, uid) \ + if ((seen & M (AT_##UID)) == 0) var ^= __get##uid () + SEE (UID, uid, uid); + SEE (EUID, uid, euid); + SEE (GID, gid, gid); + SEE (EGID, gid, egid); #endif - INTUSE(__libc_enable_secure) = uid != euid || gid != egid; + /* If one of the two pairs of IDs does not mattch this is a setuid + or setgid run. */ + INTUSE(__libc_enable_secure) = uid | gid; #ifndef HAVE_AUX_PAGESIZE if (GL(dl_pagesize) == 0) |