+ mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch added to mm-hotfixes-unstable branch

+ mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: fix vma->anon_name memory leak for anonymous shmem VMAs
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: mm: fix vma->anon_name memory leak for anonymous shmem VMAs
Date: Wed, 28 Dec 2022 11:42:49 -0800

free_anon_vma_name() is missing a check for anonymous shmem VMA which
leads to a memory leak due to refcount not being dropped.  Fix this by
adding the missing check.

Link: https://lkml.kernel.org/r/20221228194249.170354-1-surenb@google.com
Fixes: d09e8ca6cb93 ("mm: anonymous shared memory naming")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: syzbot+91edf9178386a07d06a7@syzkaller.appspotmail.com
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/include/linux/mm_inline.h~mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas
+++ a/include/linux/mm_inline.h
@@ -413,7 +413,7 @@ static inline void free_anon_vma_name(st
 	 * Not using anon_vma_name because it generates a warning if mmap_lock
 	 * is not held, which might be the case here.
 	 */
-	if (!vma->vm_file)
+	if (!vma->vm_file || vma_is_anon_shmem(vma))
 		anon_vma_name_put(vma->anon_name);
 }
 
_

Patches currently in -mm which might be from surenb@google.com are

mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch

+ mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: fix vma->anon_name memory leak for anonymous shmem VMAs
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: mm: fix vma->anon_name memory leak for anonymous shmem VMAs
Date: Wed, 4 Jan 2023 16:02:40 -0800

free_anon_vma_name() is missing a check for anonymous shmem VMA which
leads to a memory leak due to refcount not being dropped.  Fix this by
calling anon_vma_name_put() unconditionally.  It will free vma->anon_name
whenever it's non-NULL.

Link: https://lkml.kernel.org/r/20230105000241.1450843-1-surenb@google.com
Fixes: d09e8ca6cb93 ("mm: anonymous shared memory naming")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reported-by: syzbot+91edf9178386a07d06a7@syzkaller.appspotmail.com
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mm_inline.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/include/linux/mm_inline.h~mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas
+++ a/include/linux/mm_inline.h
@@ -413,8 +413,7 @@ static inline void free_anon_vma_name(st
 	 * Not using anon_vma_name because it generates a warning if mmap_lock
 	 * is not held, which might be the case here.
 	 */
-	if (!vma->vm_file)
-		anon_vma_name_put(vma->anon_name);
+	anon_vma_name_put(vma->anon_name);
 }
 
 static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
_

Patches currently in -mm which might be from surenb@google.com are

mm-fix-vma-anon_name-memory-leak-for-anonymous-shmem-vmas.patch