From: Alan Modra <amodra@gmail.com>
To: binutils@sourceware.org
Subject: ubsan: som.c undefined shift in som_set_reloc_info
Date: Sat, 6 Aug 2022 18:41:24 +0930 [thread overview]
Message-ID: <Yu4wPOxQxF64wN6f@squeak.grove.modra.org> (raw)
Do the shift using unsigned variables to avoid UB on << 8.
* som.c (som_set_reloc_info): Make v unsigned. Localise some
variables to their blocks.
diff --git a/bfd/som.c b/bfd/som.c
index 90928b7641d..d33ad67561a 100644
--- a/bfd/som.c
+++ b/bfd/som.c
@@ -4941,13 +4941,9 @@ som_set_reloc_info (unsigned char *fixup,
unsigned int symcount,
bool just_count)
{
- unsigned int op, varname, deallocate_contents = 0;
+ unsigned int deallocate_contents = 0;
unsigned char *end_fixups = &fixup[end];
- const struct fixup_format *fp;
- const char *cp;
- unsigned char *save_fixup;
- int variables[26], stack[20], c, v, count, prev_fixup, *sp, saved_unwind_bits;
- const int *subop;
+ int variables[26], stack[20], count, prev_fixup, *sp, saved_unwind_bits;
arelent *rptr = internal_relocs;
unsigned int offset = 0;
@@ -4966,10 +4962,14 @@ som_set_reloc_info (unsigned char *fixup,
while (fixup < end_fixups)
{
+ const char *cp;
+ unsigned int op;
+ const struct fixup_format *fp;
+
/* Save pointer to the start of this fixup. We'll use
it later to determine if it is necessary to put this fixup
on the queue. */
- save_fixup = fixup;
+ unsigned char *save_fixup = fixup;
/* Get the fixup code and its associated format. */
op = *fixup++;
@@ -5015,11 +5015,15 @@ som_set_reloc_info (unsigned char *fixup,
while (*cp)
{
/* The variable this pass is going to compute a value for. */
- varname = *cp++;
+ unsigned int varname = *cp++;
+ const int *subop;
+ int c;
/* Start processing RHS. Continue until a NULL or '=' is found. */
do
{
+ unsigned v;
+
c = *cp++;
/* If this is a variable, push it on the stack. */
--
Alan Modra
Australia Development Lab, IBM
reply other threads:[~2022-08-06 9:11 UTC|newest]
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