The pagemap_ioctl selftest allocates memory via calloc() in several places but does not check the return values. If calloc() fails, the subsequent code will dereference a NULL pointer and crash.
Additionally, in sanity_tests(), the calloc() failure check incorrectly uses MAP_FAILED (the mmap() error constant) instead of NULL. Since calloc() returns NULL on failure, the check never triggers and a failed allocation goes undetected. Add NULL checks after each calloc() call, and fix the wrong error constant in sanity_tests(). Use ksft_exit_fail_msg() consistent with the existing error handling pattern in the file. Signed-off-by: longlong yan <[email protected]> --- tools/testing/selftests/mm/pagemap_ioctl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/pagemap_ioctl.c b/tools/testing/selftests/mm/pagemap_ioctl.c index f9bcff8e78fa..f6629f44a13d 100644 --- a/tools/testing/selftests/mm/pagemap_ioctl.c +++ b/tools/testing/selftests/mm/pagemap_ioctl.c @@ -212,6 +212,8 @@ int userfaultfd_tests(void) vec_size = mem_size/page_size; vec = calloc(vec_size, sizeof(struct page_region)); + if (!vec) + ksft_exit_fail_msg("error nomem\n"); written = pagemap_ioctl(mem, mem_size, vec, 1, PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC, vec_size - 2, PAGE_IS_WRITTEN, 0, 0, PAGE_IS_WRITTEN); @@ -699,6 +701,8 @@ int base_tests(char *prefix, char *mem, unsigned long long mem_size, int skip) vec_size = mem_size/page_size; vec = calloc(vec_size, sizeof(struct page_region)); vec2 = calloc(vec_size, sizeof(struct page_region)); + if (!vec || !vec2) + ksft_exit_fail_msg("error nomem\n"); /* 1. all new pages must be not be written (dirty) */ written = pagemap_ioctl(mem, mem_size, vec, 1, PM_SCAN_WP_MATCHING | PM_SCAN_CHECK_WPASYNC, @@ -1000,6 +1004,8 @@ int unmapped_region_tests(void) int written, len = 0x00040000; long vec_size = len / page_size; struct page_region *vec = calloc(vec_size, sizeof(struct page_region)); + if (!vec) + ksft_exit_fail_msg("error nomem\n"); /* 1. Get written pages */ written = pagemap_ioctl(start, len, vec, vec_size, 0, 0, @@ -1116,7 +1122,7 @@ int sanity_tests(void) vec = calloc(vec_size, sizeof(struct page_region)); mem = mmap(NULL, mem_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); - if (mem == MAP_FAILED || vec == MAP_FAILED) + if (mem == MAP_FAILED || !vec) ksft_exit_fail_msg("error nomem\n"); wp_init(mem, mem_size); -- 2.43.0
