* [PATCH v2] tools/perf/util: null-terminate version char array upon error
@ 2019-05-14 11:01 Donald Yandt
2019-05-14 13:36 ` Arnaldo Carvalho de Melo
2019-05-18 8:59 ` [tip:perf/core] perf machine: Null-terminate version char array upon fgets(/proc/version) error tip-bot for Donald Yandt
0 siblings, 2 replies; 3+ messages in thread
From: Donald Yandt @ 2019-05-14 11:01 UTC (permalink / raw)
To: peterz; +Cc: mingo, acme, alexander.shishkin, jolsa, linux-kernel, Donald Yandt
If fgets fails due to any other error besides end-of-file, the version char array may not even be null-terminated.
Signed-off-by: Donald Yandt <donald.yandt@gmail.com>
---
tools/perf/util/machine.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 3c520baa1..28a9541c4 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1234,8 +1234,9 @@ static char *get_kernel_version(const char *root_dir)
if (!file)
return NULL;
- version[0] = '\0';
tmp = fgets(version, sizeof(version), file);
+ if (!tmp)
+ *version = '\0';
fclose(file);
name = strstr(version, prefix);
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] tools/perf/util: null-terminate version char array upon error
2019-05-14 11:01 [PATCH v2] tools/perf/util: null-terminate version char array upon error Donald Yandt
@ 2019-05-14 13:36 ` Arnaldo Carvalho de Melo
2019-05-18 8:59 ` [tip:perf/core] perf machine: Null-terminate version char array upon fgets(/proc/version) error tip-bot for Donald Yandt
1 sibling, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2019-05-14 13:36 UTC (permalink / raw)
To: Donald Yandt
Cc: Peter Zijlstra, Ingo Molnar, Alexander Shishkin, Jiri Olsa,
linux-kernel, Yanmin Zhang
Em Tue, May 14, 2019 at 07:01:00AM -0400, Donald Yandt escreveu:
> If fgets fails due to any other error besides end-of-file, the version char array may not even be null-terminated.
Thanks, but out of curiosity, was this found just by visual inspection?
Some static analysis tool? An actual problem you stumbled when
processing some /proc/version in a custom kernel?
Also please consider adding a:
Fixes: a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host")
So that we can get this picked up by the stable kernel trees. I'm adding
it now.
Thanks!
- Arnaldo
> Signed-off-by: Donald Yandt <donald.yandt@gmail.com>
> ---
> tools/perf/util/machine.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 3c520baa1..28a9541c4 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -1234,8 +1234,9 @@ static char *get_kernel_version(const char *root_dir)
> if (!file)
> return NULL;
>
> - version[0] = '\0';
> tmp = fgets(version, sizeof(version), file);
> + if (!tmp)
> + *version = '\0';
> fclose(file);
>
> name = strstr(version, prefix);
> --
> 2.20.1
--
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:perf/core] perf machine: Null-terminate version char array upon fgets(/proc/version) error
2019-05-14 11:01 [PATCH v2] tools/perf/util: null-terminate version char array upon error Donald Yandt
2019-05-14 13:36 ` Arnaldo Carvalho de Melo
@ 2019-05-18 8:59 ` tip-bot for Donald Yandt
1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Donald Yandt @ 2019-05-18 8:59 UTC (permalink / raw)
To: linux-tip-commits
Cc: alexander.shishkin, mingo, linux-kernel, peterz, hpa,
yanmin_zhang, acme, jolsa, tglx, donald.yandt, avi
Commit-ID: 30ba5b0e66c872faa416a458d32cc3956ecb548a
Gitweb: https://git.kernel.org/tip/30ba5b0e66c872faa416a458d32cc3956ecb548a
Author: Donald Yandt <donald.yandt@gmail.com>
AuthorDate: Tue, 14 May 2019 07:01:00 -0400
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 15 May 2019 16:36:47 -0300
perf machine: Null-terminate version char array upon fgets(/proc/version) error
If fgets() fails due to any other error besides end-of-file, the version
char array may not even be null-terminated.
Signed-off-by: Donald Yandt <donald.yandt@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Fixes: a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host")
Link: http://lkml.kernel.org/r/20190514110100.22019-1-donald.yandt@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/machine.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 3c520baa198c..28a9541c4835 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1234,8 +1234,9 @@ static char *get_kernel_version(const char *root_dir)
if (!file)
return NULL;
- version[0] = '\0';
tmp = fgets(version, sizeof(version), file);
+ if (!tmp)
+ *version = '\0';
fclose(file);
name = strstr(version, prefix);
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2019-05-14 11:01 [PATCH v2] tools/perf/util: null-terminate version char array upon error Donald Yandt
2019-05-14 13:36 ` Arnaldo Carvalho de Melo
2019-05-18 8:59 ` [tip:perf/core] perf machine: Null-terminate version char array upon fgets(/proc/version) error tip-bot for Donald Yandt
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