[PATCH] perf tools: fix off-by-one comparison on maximum code

[PATCH] perf tools: fix off-by-one comparison on maximum code

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The check for the maximum code is off-by-one; the current
comparison of a code that is INTEL_PT_ERR_MAX will cause the
strlcpy to perform an out of bounds array access on the
intel_pt_err_msgs array. Fix this with a >= comparison.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 9409d01..9c8f15d 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -356,7 +356,7 @@ static const char *intel_pt_err_msgs[] = {
 
 int intel_pt__strerror(int code, char *buf, size_t buflen)
 {
-	if (code < 1 || code > INTEL_PT_ERR_MAX)
+	if (code < 1 || code >= INTEL_PT_ERR_MAX)
 		code = INTEL_PT_ERR_UNK;
 	strlcpy(buf, intel_pt_err_msgs[code], buflen);
 	return 0;
-- 
2.7.4

Re: [PATCH] perf tools: fix off-by-one comparison on maximum code

[Arnaldo Carvalho de Melo]

Em Sun, Apr 24, 2016 at 07:56:43PM +0100, Colin King escreveu:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The check for the maximum code is off-by-one; the current
> comparison of a code that is INTEL_PT_ERR_MAX will cause the
> strlcpy to perform an out of bounds array access on the
> intel_pt_err_msgs array. Fix this with a >= comparison.

Applied, thanks.

- Arnaldo
 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> index 9409d01..9c8f15d 100644
> --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
> @@ -356,7 +356,7 @@ static const char *intel_pt_err_msgs[] = {
>  
>  int intel_pt__strerror(int code, char *buf, size_t buflen)
>  {
> -	if (code < 1 || code > INTEL_PT_ERR_MAX)
> +	if (code < 1 || code >= INTEL_PT_ERR_MAX)
>  		code = INTEL_PT_ERR_UNK;
>  	strlcpy(buf, intel_pt_err_msgs[code], buflen);
>  	return 0;
> -- 
> 2.7.4

[tip:perf/core] perf intel-pt: Fix off-by-one comparison on maximum code

[tip-bot for Colin Ian King]

Commit-ID:  c0664893050cc6b2d8b02d3e035f82fbfd0cd4cf
Gitweb:     http://git.kernel.org/tip/c0664893050cc6b2d8b02d3e035f82fbfd0cd4cf
Author:     Colin Ian King <colin.king@canonical.com>
AuthorDate: Sun, 24 Apr 2016 19:56:43 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 25 Apr 2016 20:35:59 -0300

perf intel-pt: Fix off-by-one comparison on maximum code

The check for the maximum code is off-by-one; the current comparison of
a code that is INTEL_PT_ERR_MAX will cause the strlcpy to perform an out
of bounds array access on the intel_pt_err_msgs array.

Fix this with a >= comparison.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461524203-10224-1-git-send-email-colin.king@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
index 9409d01..9c8f15d 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -356,7 +356,7 @@ static const char *intel_pt_err_msgs[] = {
 
 int intel_pt__strerror(int code, char *buf, size_t buflen)
 {
-	if (code < 1 || code > INTEL_PT_ERR_MAX)
+	if (code < 1 || code >= INTEL_PT_ERR_MAX)
 		code = INTEL_PT_ERR_UNK;
 	strlcpy(buf, intel_pt_err_msgs[code], buflen);
 	return 0;