elf: Fix UB on _dl_map_object_from_fd

On 32-bit architecture ubsan triggers:

UBSAN: Undefined behaviour in dl-load.c:1345:54 pointer index expression with base 0x00612508 overflowed  to 0xf7c3a508

Use explicit uintptr_t operation instead.
Reviewed-by: Florian Weimer <fweimer@redhat.com>

diff --git a/elf/dl-load.c b/elf/dl-load.c
index bf29ec725d57adb960f4690f23281aa33e33ca26..6e26ef05837004e4d3f7e9b268aa7b92d9f5c7fc 100644 (file)
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -1340,7 +1340,7 @@ cannot enable executable stack as shared object requires");
 
   /* Adjust the address of the TLS initialization image.  */
   if (l->l_tls_initimage != NULL)
-    l->l_tls_initimage = (char *) l->l_tls_initimage + l->l_addr;
+    l->l_tls_initimage = (void*)((uintptr_t)l->l_tls_initimage + l->l_addr);
 
   /* Process program headers again after load segments are mapped in
      case processing requires accessing those segments.  Scan program