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[binutils-gdb] MIPS/GAS: Fix null pointer dereferences in R6 PC-relative relocation checks
- From: Maciej W.Rozycki <macro at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 21 Jun 2016 22:04:47 -0000
- Subject: [binutils-gdb] MIPS/GAS: Fix null pointer dereferences in R6 PC-relative relocation checks
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=717ba204e06d88ed68441e236da3688a92cf054c
commit 717ba204e06d88ed68441e236da3688a92cf054c
Author: Maciej W. Rozycki <macro@imgtec.com>
Date: Tue Jun 21 20:12:00 2016 +0100
MIPS/GAS: Fix null pointer dereferences in R6 PC-relative relocation checks
Avoid segmentation faults in alignment checks made in `md_apply_fix' for
BFD_RELOC_MIPS_18_PCREL_S3 and BFD_RELOC_MIPS_19_PCREL_S2 relocations
caused by dereferencing `fixP->fx_addsy' which will be null if the
relocation processed has been fully resolved.
gas/
* config/tc-mips.c (md_apply_fix) <BFD_RELOC_MIPS_18_PCREL_S3>
<BFD_RELOC_MIPS_19_PCREL_S2>: Avoid null pointer dereferences
via `fixP->fx_addsy'.
Diff:
---
gas/ChangeLog | 6 ++++++
gas/config/tc-mips.c | 4 ++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/gas/ChangeLog b/gas/ChangeLog
index 45a5054..6ccbaa2 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,11 @@
2016-06-21 Maciej W. Rozycki <macro@imgtec.com>
+ * config/tc-mips.c (md_apply_fix) <BFD_RELOC_MIPS_18_PCREL_S3>
+ <BFD_RELOC_MIPS_19_PCREL_S2>: Avoid null pointer dereferences
+ via `fixP->fx_addsy'.
+
+2016-06-21 Maciej W. Rozycki <macro@imgtec.com>
+
* config/tc-mips.c (md_pcrel_from) <BFD_RELOC_MIPS_18_PCREL_S3>:
Calculate relocation from the containing aligned doubleword.
(tc_gen_reloc) <BFD_RELOC_MIPS_18_PCREL_S3>: Calculate the
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index 74f7e00..c598806 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -15034,7 +15034,7 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
break;
case BFD_RELOC_MIPS_18_PCREL_S3:
- if ((S_GET_VALUE (fixP->fx_addsy) & 0x7) != 0)
+ if (fixP->fx_addsy && (S_GET_VALUE (fixP->fx_addsy) & 0x7) != 0)
as_bad_where (fixP->fx_file, fixP->fx_line,
_("PC-relative access using misaligned symbol (%lx)"),
(long) S_GET_VALUE (fixP->fx_addsy));
@@ -15050,7 +15050,7 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
if ((*valP & 0x3) != 0)
as_bad_where (fixP->fx_file, fixP->fx_line,
_("PC-relative access to misaligned address (%lx)"),
- (long) (S_GET_VALUE (fixP->fx_addsy) + fixP->fx_offset));
+ (long) *valP);
gas_assert (!fixP->fx_done);
break;