* [PATCH] selftests/lsm: Fix memory leak in attr_lsm_count
@ 2026-07-03 2:52 Wang Yan
2026-07-03 3:01 ` William Roberts
0 siblings, 1 reply; 5+ messages in thread
From: Wang Yan @ 2026-07-03 2:52 UTC (permalink / raw)
To: linux-security-module
Cc: paul, jmorris, serge, shuah, casey, mic, linux-kselftest,
linux-kernel, Wang Yan
The calloc-allocated buffer in attr_lsm_count() is never released on
any exit path, including both the normal return path and the early
return when read_sysfs_lsms fails, resulting in a heap memory leak.
Add free() for the buffer on all return branches to fix the leak.
Fixes: d3d929a8b0cd ("LSM: selftests for Linux Security Module syscalls")
Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
---
tools/testing/selftests/lsm/common.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/lsm/common.c b/tools/testing/selftests/lsm/common.c
index 9ad258912646..4fa8310750a0 100644
--- a/tools/testing/selftests/lsm/common.c
+++ b/tools/testing/selftests/lsm/common.c
@@ -76,6 +76,7 @@ int attr_lsm_count(void)
return 0;
if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
+ free(names);
return 0;
if (strstr(names, "selinux"))
@@ -85,5 +86,6 @@ int attr_lsm_count(void)
if (strstr(names, "apparmor"))
count++;
+ free(names);
return count;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] selftests/lsm: Fix memory leak in attr_lsm_count
2026-07-03 2:52 [PATCH] selftests/lsm: Fix memory leak in attr_lsm_count Wang Yan
@ 2026-07-03 3:01 ` William Roberts
2026-07-03 12:09 ` [PATCH v2] " Wang Yan
0 siblings, 1 reply; 5+ messages in thread
From: William Roberts @ 2026-07-03 3:01 UTC (permalink / raw)
To: Wang Yan
Cc: linux-security-module, paul, jmorris, serge, shuah, casey, mic,
linux-kselftest, linux-kernel
On Thu, Jul 2, 2026 at 9:53 PM Wang Yan <wangyan01@kylinos.cn> wrote:
>
> The calloc-allocated buffer in attr_lsm_count() is never released on
> any exit path, including both the normal return path and the early
> return when read_sysfs_lsms fails, resulting in a heap memory leak.
>
> Add free() for the buffer on all return branches to fix the leak.
>
> Fixes: d3d929a8b0cd ("LSM: selftests for Linux Security Module syscalls")
> Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
> ---
> tools/testing/selftests/lsm/common.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/tools/testing/selftests/lsm/common.c b/tools/testing/selftests/lsm/common.c
> index 9ad258912646..4fa8310750a0 100644
> --- a/tools/testing/selftests/lsm/common.c
> +++ b/tools/testing/selftests/lsm/common.c
> @@ -76,6 +76,7 @@ int attr_lsm_count(void)
> return 0;
>
> if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
> + free(names);
> return 0;
Did you test this, let alone even compile it? All the C code after
this return is dead code.
Please ensure that you test and compile your patches checking for
warnings. Sending
untested patches is "spammy".
>
> if (strstr(names, "selinux"))
> @@ -85,5 +86,6 @@ int attr_lsm_count(void)
> if (strstr(names, "apparmor"))
> count++;
>
> + free(names);
Do this instead:
if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
goto out;
<existing code>
out:
free(names);
> return count;
> }
> --
> 2.25.1
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2] selftests/lsm: Fix memory leak in attr_lsm_count
2026-07-03 3:01 ` William Roberts
@ 2026-07-03 12:09 ` Wang Yan
2026-07-03 17:56 ` William Roberts
2026-07-07 19:13 ` Paul Moore
0 siblings, 2 replies; 5+ messages in thread
From: Wang Yan @ 2026-07-03 12:09 UTC (permalink / raw)
To: bill.c.roberts
Cc: casey, jmorris, linux-kernel, linux-kselftest,
linux-security-module, mic, paul, serge, shuah, wangyan01
The calloc-allocated buffer in attr_lsm_count() is never released on
any exit path, including both the normal return path and the early
return when read_sysfs_lsms fails, resulting in a heap memory leak.
Add free() for the buffer on all return branches to fix the leak.
Fixes: d3d929a8b0cd ("LSM: selftests for Linux Security Module syscalls")
Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
---
tools/testing/selftests/lsm/common.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/lsm/common.c b/tools/testing/selftests/lsm/common.c
index 9ad258912646..927dce4f04cb 100644
--- a/tools/testing/selftests/lsm/common.c
+++ b/tools/testing/selftests/lsm/common.c
@@ -76,7 +76,7 @@ int attr_lsm_count(void)
return 0;
if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
- return 0;
+ goto out;
if (strstr(names, "selinux"))
count++;
@@ -85,5 +85,7 @@ int attr_lsm_count(void)
if (strstr(names, "apparmor"))
count++;
+out:
+ free(names);
return count;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2] selftests/lsm: Fix memory leak in attr_lsm_count
2026-07-03 12:09 ` [PATCH v2] " Wang Yan
@ 2026-07-03 17:56 ` William Roberts
2026-07-07 19:13 ` Paul Moore
1 sibling, 0 replies; 5+ messages in thread
From: William Roberts @ 2026-07-03 17:56 UTC (permalink / raw)
To: Wang Yan
Cc: casey, jmorris, linux-kernel, linux-kselftest,
linux-security-module, mic, paul, serge, shuah
On Fri, Jul 3, 2026 at 7:10 AM Wang Yan <wangyan01@kylinos.cn> wrote:
>
> The calloc-allocated buffer in attr_lsm_count() is never released on
> any exit path, including both the normal return path and the early
> return when read_sysfs_lsms fails, resulting in a heap memory leak.
>
> Add free() for the buffer on all return branches to fix the leak.
>
> Fixes: d3d929a8b0cd ("LSM: selftests for Linux Security Module syscalls")
> Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
> ---
> tools/testing/selftests/lsm/common.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/lsm/common.c b/tools/testing/selftests/lsm/common.c
> index 9ad258912646..927dce4f04cb 100644
> --- a/tools/testing/selftests/lsm/common.c
> +++ b/tools/testing/selftests/lsm/common.c
> @@ -76,7 +76,7 @@ int attr_lsm_count(void)
> return 0;
>
> if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
> - return 0;
> + goto out;
>
> if (strstr(names, "selinux"))
> count++;
> @@ -85,5 +85,7 @@ int attr_lsm_count(void)
> if (strstr(names, "apparmor"))
> count++;
>
> +out:
> + free(names);
> return count;
> }
> --
> 2.25.1
>
Reviewed-by: William Roberts <bill.c.roberts@gmail.com>
Tested-by: William Roberts <bill.c.roberts@gmail.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] selftests/lsm: Fix memory leak in attr_lsm_count
2026-07-03 12:09 ` [PATCH v2] " Wang Yan
2026-07-03 17:56 ` William Roberts
@ 2026-07-07 19:13 ` Paul Moore
1 sibling, 0 replies; 5+ messages in thread
From: Paul Moore @ 2026-07-07 19:13 UTC (permalink / raw)
To: Wang Yan, bill.c.roberts
Cc: casey, jmorris, linux-kernel, linux-kselftest,
linux-security-module, mic, serge, shuah, wangyan01
On Jul 3, 2026 Wang Yan <wangyan01@kylinos.cn> wrote:
>
> The calloc-allocated buffer in attr_lsm_count() is never released on
> any exit path, including both the normal return path and the early
> return when read_sysfs_lsms fails, resulting in a heap memory leak.
>
> Add free() for the buffer on all return branches to fix the leak.
>
> Fixes: d3d929a8b0cd ("LSM: selftests for Linux Security Module syscalls")
> Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
> Reviewed-by: William Roberts <bill.c.roberts@gmail.com>
> Tested-by: William Roberts <bill.c.roberts@gmail.com>
> ---
> tools/testing/selftests/lsm/common.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
Merged into lsm/dev, thanks!
--
paul-moore.com
^ permalink raw reply [flat|nested] 5+ messages in thread
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2026-07-03 2:52 [PATCH] selftests/lsm: Fix memory leak in attr_lsm_count Wang Yan
2026-07-03 3:01 ` William Roberts
2026-07-03 12:09 ` [PATCH v2] " Wang Yan
2026-07-03 17:56 ` William Roberts
2026-07-07 19:13 ` Paul Moore
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