2018-01-17 13:16:19

by Thomas-Mich Richter

Subject: [PATCH] perf record: Fix failed memory allocation for get_cpuid_str

In x86 architecture dependend part function
get_cpuid_str() mallocs a 128 byte buffer, but does not
check if the memory allocation succeeded or not.
When the memory allocation fails, function __get_cpuid()
is called with first parameter being a NULL pointer.
However this function references its first parameter
and operates on a NULL pointer which might cause core
dumps.

Signed-off-by: Thomas Richter <[email protected]>
---
tools/perf/arch/x86/util/header.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/x86/util/header.c b/tools/perf/arch/x86/util/header.c
index 33027c5e6f92..c6b5204e0280 100644
--- a/tools/perf/arch/x86/util/header.c
+++ b/tools/perf/arch/x86/util/header.c
@@ -70,7 +70,7 @@ get_cpuid_str(void)
{
char *buf = malloc(128);

- if (__get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
+ if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
free(buf);
return NULL;
}
--
2.13.4

2018-01-17 13:32:13

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf record: Fix failed memory allocation for get_cpuid_str

Em Wed, Jan 17, 2018 at 02:16:11PM +0100, Thomas Richter escreveu:
> In x86 architecture dependend part function
> get_cpuid_str() mallocs a 128 byte buffer, but does not
> check if the memory allocation succeeded or not.
> When the memory allocation fails, function __get_cpuid()
> is called with first parameter being a NULL pointer.
> However this function references its first parameter
> and operates on a NULL pointer which might cause core
> dumps.

Thanks, applied.

- Arnaldo

> Signed-off-by: Thomas Richter <[email protected]>
> ---
> tools/perf/arch/x86/util/header.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/arch/x86/util/header.c b/tools/perf/arch/x86/util/header.c
> index 33027c5e6f92..c6b5204e0280 100644
> --- a/tools/perf/arch/x86/util/header.c
> +++ b/tools/perf/arch/x86/util/header.c
> @@ -70,7 +70,7 @@ get_cpuid_str(void)
> {
> char *buf = malloc(128);
>
> - if (__get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
> + if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
> free(buf);
> return NULL;
> }
> --
> 2.13.4

2018-01-17 16:40:24

by tip-bot for Vasyl Gomonovych

Subject: [tip:perf/core] perf record: Fix failed memory allocation for get_cpuid_str

Commit-ID: 81fccd6ca507d3b2012eaf1edeb9b1dbf4bd22db
Gitweb: https://git.kernel.org/tip/81fccd6ca507d3b2012eaf1edeb9b1dbf4bd22db
Author: Thomas Richter <[email protected]>
AuthorDate: Wed, 17 Jan 2018 14:16:11 +0100
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Wed, 17 Jan 2018 10:31:25 -0300

perf record: Fix failed memory allocation for get_cpuid_str

In x86 architecture dependend part function get_cpuid_str() mallocs a
128 byte buffer, but does not check if the memory allocation succeeded
or not.

When the memory allocation fails, function __get_cpuid() is called with
first parameter being a NULL pointer. However this function references
its first parameter and operates on a NULL pointer which might cause
core dumps.

Signed-off-by: Thomas Richter <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hendrik Brueckner <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/arch/x86/util/header.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/arch/x86/util/header.c b/tools/perf/arch/x86/util/header.c
index b626d2b..fb0d71a 100644
--- a/tools/perf/arch/x86/util/header.c
+++ b/tools/perf/arch/x86/util/header.c
@@ -70,7 +70,7 @@ get_cpuid_str(struct perf_pmu *pmu __maybe_unused)
{
char *buf = malloc(128);

- if (__get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
+ if (buf && __get_cpuid(buf, 128, "%s-%u-%X$") < 0) {
free(buf);
return NULL;
}