Thread (5 messages) 5 messages, 3 authors, 5d ago

Re: [PATCH] selftests/lsm: Fix memory leak in attr_lsm_count

From: William Roberts <hidden>
Date: 2026-07-03 03:01:46
Also in: linux-kselftest, lkml

On Thu, Jul 2, 2026 at 9:53 PM Wang Yan [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
---
 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".
quoted hunk ↗ jump to hunk
        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
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