diff options
| author | Anshuman <anshumantewari123@gmail.com> | 2026-08-19 17:44:26 +0530 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-08-24 18:43:27 -0700 |
| commit | d16e52a9ba9ed5060f97ed3191017a21b5fc25a2 (patch) | |
| tree | 647f9e409ad42147064439e5d03ae760ce6a9357 /tools | |
| parent | f9dc428249ed962a70acf301f01eae8578449161 (diff) | |
selftests/mm: check stat() return value in khugepaged get_finfo()
get_finfo() calls stat() to get metadata about the target directory, but
never checks the return value. On failure, stat() returns -1 and leaves
path_stat unmodified, so path_stat.st_mode may contain uninitialized stack
data.
The code then checks S_ISDIR(path_stat.st_mode) against this potentially
garbage value. This can produce a misleading "Not a directory" error when
the real problem is a nonexistent or inaccessible path, or, in the worst
case, the check could pass by chance on garbage data and let the function
continue using an invalid path_stat for the rest of its logic.
Check the return value and fail with a clear error message if stat()
fails, matching the error-handling style already used for statfs() and
read_file() later in the same function.
Link: https://lore.kernel.org/20260819121426.49500-1-anshumantewari123@gmail.com
Signed-off-by: Anshuman <anshumantewari123@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Reviewed-by: Sarthak Sharma <sarthak.sharma@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/mm/khugepaged.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index d3a53673e1f9..1d2d6bd72fd2 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -124,7 +124,8 @@ static void get_finfo(const char *dir) char *str, *end; finfo.dir = dir; - stat(finfo.dir, &path_stat); + if (stat(finfo.dir, &path_stat)) + ksft_exit_fail_perror("stat()"); if (!S_ISDIR(path_stat.st_mode)) ksft_exit_fail_msg("%s: Not a directory (%s)\n", __func__, finfo.dir); if (snprintf(finfo.path, sizeof(finfo.path), "%s/" TEST_FILE, |