+ selftests-mm-fix-potential-wild-pointer-access-of-getline-due-to-missing-init.patch added to mm-hotfixes-unstable branch

The patch titled
     Subject: selftests/mm: fix potential wild pointer access of getline due to missing init
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     selftests-mm-fix-potential-wild-pointer-access-of-getline-due-to-missing-init.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-fix-potential-wild-pointer-access-of-getline-due-to-missing-init.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Chris Gellermann <[email protected]>
Subject: selftests/mm: fix potential wild pointer access of getline due to missing init
Date: Wed, 22 Jul 2026 15:02:46 +0200

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.

Link: https://lore.kernel.org/[email protected]
Link: https://pubs.opengroup.org/onlinepubs/9799919799/functions/getline.html [1]
Fixes: 26b4224d9961 ("selftests: expanding more mlock selftest")
Signed-off-by: Chris Gellermann <[email protected]>
Acked-by: David Hildenbrand (arm) <[email protected]>
Reviewed-by: Lorenzo Stoakes <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 tools/testing/selftests/mm/mlock-random-test.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/testing/selftests/mm/mlock-random-test.c~selftests-mm-fix-potential-wild-pointer-access-of-getline-due-to-missing-init
+++ a/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;
 
_

Patches currently in -mm which might be from [email protected] are

selftests-clone3-fix-wild-pointer-access-of-getline-due-to-missing-init.patch
selftests-mm-fix-potential-wild-pointer-access-of-getline-due-to-missing-init.patch