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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: UHuUkeaJWB06WWfFuRYbOrrKlNeFNlAxagm1znWr9AXDkK6P6v/BORUd9eDAh2gv9ymOHb39csDoWEMjgGlQUDOa3n1qio0tdMujdseTfS688HzDUsvvtVX73ZWVglbrAUK9ag5SuQVnRdF3IKl+P62gTIa0Fk0YsVi9FfOhcNvUdHWuCN4nFei5TSulj94o1XrinAw+wTVusDBQ+OH0v9MswaWWKghrIRbD9ArQtH1LIeno0j6I+3erVFRuHfTAkpcAusatLUfNt6lNPiFYe2zNDEy/tcadOfRldwDNtbvHY3zaY4s9wCOPfDFo08S0R9rES8R6/uv+vqSb3j18o5qX2jrib/EktMmf5+rxpWavrPUayNVXtNZAo1MQuSEtBbDyqWz8EAwtvSmbAqiH2t/bLJZRSmBVFrhPP/WGZeMFAnwUTe2AhKxy1zwiQtyd X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Aug 2026 04:15:28.1713 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: ed3631a0-258e-4f32-2cd9-08defe71aac1 X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: DB1PEPF000509FE.eurprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PA4PR08MB6254 On 8/19/26 5:44 PM, Anshuman wrote: > 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. > > Signed-off-by: Anshuman LGTM, so: Reviewed-by: Sarthak Sharma > --- > tools/testing/selftests/mm/khugepaged.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c > index 10e8dedcb..2240a9b4f 100644 > --- a/tools/testing/selftests/mm/khugepaged.c > +++ b/tools/testing/selftests/mm/khugepaged.c > @@ -121,7 +121,8 @@ 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,