lib: smb_threads: fix access before init bug

talloc_stackframe_internal() calls SMB_THREAD_GET_TLS(global_ts)  which
calls smb_get_tls_pthread() in the POSIX pthread wrapper implementation.

If SMB_THREAD_SET_TLS() hasn't been called before, global_ts is NULL and
smb_get_tls_pthread dereferences it so it crashes.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13505

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/lib/util/smb_threads.h b/lib/util/smb_threads.h
index 9a096167743383c76b9d00d19a3766f826421d91..67d05b8c41132a67cd43e8daaf172391f4d5a846 100644 (file)
--- a/lib/util/smb_threads.h
+++ b/lib/util/smb_threads.h
@@ -119,6 +119,9 @@ static int smb_set_tls_pthread(void *pkey, const void *pval, const char *locatio
  \
 static void *smb_get_tls_pthread(void *pkey, const char *location) \
 { \
+       if (pkey == NULL) { \
+               return NULL; \
+       } \
         return pthread_getspecific(*(pthread_key_t *)pkey); \
 } \
  \