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Fix seg-fault in readelf when decoding corrupt IA64 unwind information.
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	PR binutils/18420
	* ia64-unwind.c (unw_decode): Add end parameter.  Pass parameter
	on to decode functions.
	(unw_devode_p2_p5): Pass end paraemter to UNW_DEC_SPILL_MASK.
	(UNW_DEC_SPILL_MASK): Add end parameter.  Check that unw_rlen does
	not take us beyond the end of the buffer.
	* ia64-unwind.h (unw_decode): Update prototype.
	* readelf.c (dump_ia64_unwind): Pass end pointer to unw_decode.
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@nickclifton
nickclifton committed May 18, 2015
1 parent 35d7c43 commit b4477bc
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11 changes: 11 additions & 0 deletions binutils/ChangeLog
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Original file line number Diff line number Diff line change
@@ -1,3 +1,14 @@
2015-05-18 Nick Clifton <[email protected]>

PR binutils/18420
* ia64-unwind.c (unw_decode): Add end parameter. Pass parameter
on to decode functions.
(unw_devode_p2_p5): Pass end paraemter to UNW_DEC_SPILL_MASK.
(UNW_DEC_SPILL_MASK): Add end parameter. Check that unw_rlen does
not take us beyond the end of the buffer.
* ia64-unwind.h (unw_decode): Update prototype.
* readelf.c (dump_ia64_unwind): Pass end pointer to unw_decode.

2015-05-15 H.J. Lu <[email protected]>

* readelf.c (dump_section_as_strings): Change pointers from
Expand Down
2 changes: 1 addition & 1 deletion binutils/readelf.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6735,7 +6735,7 @@ dump_ia64_unwind (struct ia64_unw_aux_info * aux)
if (end > aux->info + aux->info_size)
end = aux->info + aux->info_size;
for (dp = head + 8; dp < end;)
dp = unw_decode (dp, in_body, & in_body);
dp = unw_decode (dp, in_body, & in_body, end);
}

free (aux->funtab);
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90 changes: 39 additions & 51 deletions binutils/unwind-ia64.c
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Original file line number Diff line number Diff line change
Expand Up @@ -349,14 +349,22 @@ typedef bfd_vma unw_word;
printf ("\t%s:spill_base(pspoff=0x10-0x%lx)\n", \
fmt, 4*(unsigned long)pspoff)

#define UNW_DEC_SPILL_MASK(fmt, dp, arg) \
do \
{ \
static const char *spill_type = "-frb"; \
#define UNW_DEC_SPILL_MASK(fmt, dp, arg, end) \
do \
{ \
static const char *spill_type = "-frb"; \
unsigned const char *imaskp = dp; \
unsigned char mask = 0; \
bfd_vma insn = 0; \
\
unsigned char mask = 0; \
bfd_vma insn = 0; \
\
/* PR 18420. */ \
if ((dp + (unw_rlen / 4)) > end) \
{ \
printf ("\nERROR: unwind length too long (0x%lx > 0x%lx)\n\n",\
(long) (unw_rlen / 4), (long)(end - dp)); \
/* FIXME: Should we reset unw_rlen ? */ \
break; \
} \
printf ("\t%s:spill_mask(imask=[", fmt); \
for (insn = 0; insn < unw_rlen; ++insn) \
{ \
Expand Down Expand Up @@ -533,36 +541,6 @@ typedef bfd_vma unw_word;
* UNW_DEC_SPILL_SPREL_P(fmt,qp,t,abreg,pspoff,arg)
*/

static unw_word unw_decode_uleb128 (const unsigned char **);
static const unsigned char *unw_decode_x1
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_x2
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_x3
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_x4
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_r1
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_r2
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_r3
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_p1
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_p2_p5
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_p6
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_p7_p10
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_b1
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_b2
(const unsigned char *, unsigned int, void *);
static const unsigned char *unw_decode_b3_x4
(const unsigned char *, unsigned int, void *);

static unw_word
unw_decode_uleb128 (const unsigned char **dpp)
{
Expand Down Expand Up @@ -671,7 +649,8 @@ unw_decode_x4 (const unsigned char *dp, unsigned int code ATTRIBUTE_UNUSED,
}

static const unsigned char *
unw_decode_r1 (const unsigned char *dp, unsigned int code, void *arg)
unw_decode_r1 (const unsigned char *dp, unsigned int code, void *arg,
const unsigned char * end ATTRIBUTE_UNUSED)
{
int body = (code & 0x20) != 0;
unw_word rlen;
Expand All @@ -682,7 +661,8 @@ unw_decode_r1 (const unsigned char *dp, unsigned int code, void *arg)
}

static const unsigned char *
unw_decode_r2 (const unsigned char *dp, unsigned int code, void *arg)
unw_decode_r2 (const unsigned char *dp, unsigned int code, void *arg,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unsigned char byte1, mask, grsave;
unw_word rlen;
Expand All @@ -697,7 +677,8 @@ unw_decode_r2 (const unsigned char *dp, unsigned int code, void *arg)
}

static const unsigned char *
unw_decode_r3 (const unsigned char *dp, unsigned int code, void *arg)
unw_decode_r3 (const unsigned char *dp, unsigned int code, void *arg,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unw_word rlen;

Expand All @@ -708,7 +689,8 @@ unw_decode_r3 (const unsigned char *dp, unsigned int code, void *arg)

static const unsigned char *
unw_decode_p1 (const unsigned char *dp, unsigned int code,
void *arg ATTRIBUTE_UNUSED)
void *arg ATTRIBUTE_UNUSED,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unsigned char brmask = (code & 0x1f);

Expand All @@ -718,7 +700,8 @@ unw_decode_p1 (const unsigned char *dp, unsigned int code,

static const unsigned char *
unw_decode_p2_p5 (const unsigned char *dp, unsigned int code,
void *arg ATTRIBUTE_UNUSED)
void *arg ATTRIBUTE_UNUSED,
const unsigned char * end)
{
if ((code & 0x10) == 0)
{
Expand Down Expand Up @@ -777,7 +760,7 @@ unw_decode_p2_p5 (const unsigned char *dp, unsigned int code,
}
}
else if ((code & 0x7) == 0)
UNW_DEC_SPILL_MASK ("P4", dp, arg);
UNW_DEC_SPILL_MASK ("P4", dp, arg, end);
else if ((code & 0x7) == 1)
{
unw_word grmask, frmask, byte1, byte2, byte3;
Expand All @@ -797,7 +780,8 @@ unw_decode_p2_p5 (const unsigned char *dp, unsigned int code,

static const unsigned char *
unw_decode_p6 (const unsigned char *dp, unsigned int code,
void *arg ATTRIBUTE_UNUSED)
void *arg ATTRIBUTE_UNUSED,
const unsigned char * end ATTRIBUTE_UNUSED)
{
int gregs = (code & 0x10) != 0;
unsigned char mask = (code & 0x0f);
Expand All @@ -810,7 +794,8 @@ unw_decode_p6 (const unsigned char *dp, unsigned int code,
}

static const unsigned char *
unw_decode_p7_p10 (const unsigned char *dp, unsigned int code, void *arg)
unw_decode_p7_p10 (const unsigned char *dp, unsigned int code, void *arg,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unsigned char r, byte1, byte2;
unw_word t, size;
Expand Down Expand Up @@ -984,7 +969,8 @@ unw_decode_p7_p10 (const unsigned char *dp, unsigned int code, void *arg)

static const unsigned char *
unw_decode_b1 (const unsigned char *dp, unsigned int code,
void *arg ATTRIBUTE_UNUSED)
void *arg ATTRIBUTE_UNUSED,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unw_word label = (code & 0x1f);

Expand All @@ -997,7 +983,8 @@ unw_decode_b1 (const unsigned char *dp, unsigned int code,

static const unsigned char *
unw_decode_b2 (const unsigned char *dp, unsigned int code,
void *arg ATTRIBUTE_UNUSED)
void *arg ATTRIBUTE_UNUSED,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unw_word t;

Expand All @@ -1007,7 +994,8 @@ unw_decode_b2 (const unsigned char *dp, unsigned int code,
}

static const unsigned char *
unw_decode_b3_x4 (const unsigned char *dp, unsigned int code, void *arg)
unw_decode_b3_x4 (const unsigned char *dp, unsigned int code, void *arg,
const unsigned char * end ATTRIBUTE_UNUSED)
{
unw_word t, ecount, label;

Expand Down Expand Up @@ -1044,7 +1032,7 @@ unw_decode_b3_x4 (const unsigned char *dp, unsigned int code, void *arg)
}

typedef const unsigned char *(*unw_decoder)
(const unsigned char *, unsigned int, void *);
(const unsigned char *, unsigned int, void *, const unsigned char *);

static const unw_decoder unw_decode_table[2][8] =
{
Expand Down Expand Up @@ -1074,12 +1062,12 @@ static const unw_decoder unw_decode_table[2][8] =
/* Decode one descriptor and return address of next descriptor. */
const unsigned char *
unw_decode (const unsigned char *dp, int inside_body,
void *ptr_inside_body)
void *ptr_inside_body, const unsigned char * end)
{
unw_decoder decoder;
unsigned char code;

code = *dp++;
decoder = unw_decode_table[inside_body][code >> 5];
return (*decoder) (dp, code, ptr_inside_body);
return (*decoder) (dp, code, ptr_inside_body, end);
}
2 changes: 1 addition & 1 deletion binutils/unwind-ia64.h
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Original file line number Diff line number Diff line change
Expand Up @@ -29,4 +29,4 @@
#define UNW_FLAG_UHANDLER(x) ((x) & 0x0000000200000000LL)
#define UNW_LENGTH(x) ((x) & 0x00000000ffffffffLL)

extern const unsigned char *unw_decode (const unsigned char *, int, void *);
extern const unsigned char *unw_decode (const unsigned char *, int, void *, const unsigned char *);

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