This is another occurrence of using getline where the code assumes that getline allocates memory to store the line, but the pointer passed to it is uninitialized and potentially a non-null pointer. This violates the Open Group Spec[1] and caused a segfault in a similar situation in selftest/clone3/clone3_set_tid. Fix it by initializing the line pointer to NULL.
The issue has been found by simply grepping through the selftest code after running into the issue in clone3_set_tid. Whether it segfaults in its current state is unknown to me. But it's good to be addressed due to defensive reasons. [1] https://pubs.opengroup.org/onlinepubs/9799919799/functions/getline.html Fixes: 26b4224d9961 ("selftests: expanding more mlock selftest") Cc: [email protected] Acked-by: David Hildenbrand (arm) <[email protected]> Reviewed-by: Lorenzo Stoakes <[email protected]> Signed-off-by: Chris Gellermann <[email protected]> --- tools/testing/selftests/mm/mlock-random-test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/mlock-random-test.c b/tools/testing/selftests/mm/mlock-random-test.c index 9d349c151360..16294bc7dae6 100644 --- a/tools/testing/selftests/mm/mlock-random-test.c +++ b/tools/testing/selftests/mm/mlock-random-test.c @@ -84,7 +84,7 @@ int get_proc_locked_vm_size(void) int get_proc_page_size(unsigned long addr) { FILE *smaps; - char *line; + char *line = NULL; unsigned long mmupage_size = 0; size_t size; -- 2.47.3
