[COMMITTED] Fuller check for invalid NSID in _dl_open.
Commit Message
This is the patch I just posted under:
Subject: Re: Build problem with ToT GCC
But in case some people didn't notice it was a proposed patch,
here it is again, just committed after Steve's verification that
it fixes the trunk-gcc warning.
Thanks,
Roland
2015-04-17 Roland McGrath <roland@hack.frob.com>
* elf/dl-open.c (_dl_open): Use __glibc_unlikely in invalid namespace
check. Reject NSID < 0 and NSID >= dl_nns, and check for DL_NNS==1,
before using NSID as an index.
@@ -619,8 +619,14 @@ no more namespaces available for dlmopen()"));
/* Never allow loading a DSO in a namespace which is empty. Such
direct placements is only causing problems. Also don't allow
loading into a namespace used for auditing. */
- else if (__builtin_expect (nsid != LM_ID_BASE && nsid != __LM_ID_CALLER, 0)
- && (GL(dl_ns)[nsid]._ns_nloaded == 0
+ else if (__glibc_unlikely (nsid != LM_ID_BASE && nsid != __LM_ID_CALLER)
+ && (__glibc_unlikely (nsid < 0 || nsid >= GL(dl_nns))
+ /* This prevents the [NSID] index expressions from being
+ evaluated, so the compiler won't think that we are
+ accessing an invalid index here in the !SHARED case where
+ DL_NNS is 1 and so any NSID != 0 is invalid. */
+ || DL_NNS == 1
+ || GL(dl_ns)[nsid]._ns_nloaded == 0
|| GL(dl_ns)[nsid]._ns_loaded->l_auditing))
_dl_signal_error (EINVAL, file, NULL,
N_("invalid target namespace in dlmopen()"));