[merged mm-stable] selftests-mm-pagemap_ioctl-fix-missing-null-checks-after-calloc.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: selftests/mm/pagemap_ioctl: fix missing NULL checks after calloc()
has been removed from the -mm tree.  Its filename was
     selftests-mm-pagemap_ioctl-fix-missing-null-checks-after-calloc.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: longlong yan <yanlonglong@kylinos.cn>
Subject: selftests/mm/pagemap_ioctl: fix missing NULL checks after calloc()
Date: Tue, 21 Jul 2026 14:36:11 +0800

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.

Link: https://lore.kernel.org/20260721063611.342-1-yanlonglong@kylinos.cn
Signed-off-by: longlong yan <yanlonglong@kylinos.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/mm/pagemap_ioctl.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/tools/testing/selftests/mm/pagemap_ioctl.c~selftests-mm-pagemap_ioctl-fix-missing-null-checks-after-calloc
+++ a/tools/testing/selftests/mm/pagemap_ioctl.c
@@ -213,6 +213,8 @@ 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);
@@ -700,6 +702,8 @@ int base_tests(char *prefix, char *mem,
 	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,
@@ -1001,6 +1005,8 @@ 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,
@@ -1163,7 +1169,7 @@ 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);
_

Patches currently in -mm which might be from yanlonglong@kylinos.cn are