PR26462 UBSAN: reloc.c:473 shift exponent 4294967295

	PR 26462
	* reloc.c (bfd_check_overflow): Return early if zero bitsize.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 18ded261a575a99dabade2c92907eaad49ef4cf6..6d3ba691da9116808d6b509c589252a7b3f5f46b 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2020-08-27  Alan Modra  <amodra@gmail.com>
+
+       PR 26462
+       * reloc.c (bfd_check_overflow): Return early if zero bitsize.
+
 2020-08-27  Alan Modra  <amodra@gmail.com>
 
        * elf32-arm.c (elf32_arm_final_link_relocate): Don't segfault

diff --git a/bfd/reloc.c b/bfd/reloc.c
index 9aba84ca81e829b3386942bbae8c04b5b7daa544..7d3479acef4ad1c187ebdd4e7b3b62351286f2f6 100644 (file)
--- a/bfd/reloc.c
+++ b/bfd/reloc.c
@@ -466,6 +466,9 @@ bfd_check_overflow (enum complain_overflow how,
   bfd_vma fieldmask, addrmask, signmask, ss, a;
   bfd_reloc_status_type flag = bfd_reloc_ok;
 
+  if (bitsize == 0)
+    return flag;
+
   /* Note: BITSIZE should always be <= ADDRSIZE, but in case it's not,
      we'll be permissive: extra bits in the field mask will
      automatically extend the address mask for purposes of the