On 8/21/26 13:44, Anshuman wrote: > The return value of strdup() is never checked before being passed to > strsep() and strcmp(). If strdup() fails and returns NULL, strsep() > returns NULL as well, and the subsequent strcmp(NULL, "all") is > undefined behavior, likely causing a crash.
In practice this is extraordinarily unlikely to ever fail. :) So I don't think we would ever experience this. > > Additionally, buf is never freed. strsep() advances the buf pointer > past the first token, so by the time buf would normally be freed, > the original pointer returned by strdup() has already been > overwritten and is no longer available. Given that parse_test_type() is called only once, nobody cares. > > Check strdup()'s return value and fail cleanly on allocation failure. > Keep a separate pointer to the original allocation so it can be > freed once buf is done being used, after all parsing has completed > successfully. > > Signed-off-by: Anshuman <[email protected]> > --- [...] That's too much churn for something that is irrelevant in practice and makes the code more complicated. So the following is better I think: >From 36d525409eb16f56e667b2f979f2c6ef112ff235 Mon Sep 17 00:00:00 2001 From: "David Hildenbrand (Arm)" <[email protected]> Date: Fri, 21 Aug 2026 15:57:57 +0200 Subject: [PATCH] selftests/mm: khugepaged: remove str_dup() usage We don't check str_dup() return value and never free it. While both things are irrelevant in practice, let's just work on argv[0] directly and avoid the str_dup(). Nobody after us needs these parts of the argv[0] string. Signed-off-by: David Hildenbrand (Arm) <[email protected]> --- tools/testing/selftests/mm/khugepaged.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index d3a53673e1f9..7520fc0483ac 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -1226,7 +1226,7 @@ static void parse_test_type(int argc, char **argv) return; } - buf = strdup(argv[0]); + buf = argv[0]; token = strsep(&buf, ":"); if (!strcmp(token, "all")) { -- 2.43.0 -- Cheers, David
