diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/generic/dl-sysdep.c | 32 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/kernel-features.h | 6 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/ldsodefs.h | 6 |
3 files changed, 24 insertions, 20 deletions
diff --git a/sysdeps/generic/dl-sysdep.c b/sysdeps/generic/dl-sysdep.c index 0f5f0fc..17e8f4d 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) diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h index 562a6c7..927701a 100644 --- a/sysdeps/unix/sysv/linux/kernel-features.h +++ b/sysdeps/unix/sysv/linux/kernel-features.h @@ -171,6 +171,12 @@ # define __ASSUME_AT_PAGESIZE 1 #endif +/* Starting with at least 2.4.0 the kernel passes the uid/gid unconditionally + up to the child. */ +#if __LINUX_KERNEL_VERSION >= 132097 +# define __ASSUME_AT_XID 1 +#endif + /* Starting with 2.4.5 kernels PPC passes the AUXV in the standard way and the mmap2 syscall made it into the official kernel. */ #if __LINUX_KERNEL_VERSION >= (132096+5) && defined __powerpc__ diff --git a/sysdeps/unix/sysv/linux/ldsodefs.h b/sysdeps/unix/sysv/linux/ldsodefs.h index 8e37f4d..a3c97c4 100644 --- a/sysdeps/unix/sysv/linux/ldsodefs.h +++ b/sysdeps/unix/sysv/linux/ldsodefs.h @@ -36,8 +36,10 @@ extern void _dl_aux_init (ElfW(auxv_t) *av) internal_function; extern void _dl_non_dynamic_init (void) internal_function; /* We can assume that the kernel always provides the AT_UID, AT_EUID, - AT_GID, and AT_EGID values in the auxiliary vector. */ -#define HAVE_AUX_XID + AT_GID, and AT_EGID values in the auxiliary vector from 2.4.0 or so on. */ +#if __ASSUME_AT_XID +# define HAVE_AUX_XID +#endif /* Starting with one of the 2.4.0 pre-releases the Linux kernel passes up the page size information. */ |