Re: [PATCH 6.5.y] mmap: fix error paths with dup_anon_vma()

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Nov 01, 2023 at 10:41:38AM -0400, Liam R. Howlett wrote:
> commit 824135c46b00df7fb369ec7f1f8607427bbebeb0 upstream
> 
> When the calling function fails after the dup_anon_vma(), the
> duplication of the anon_vma is not being undone.  Add the necessary
> unlink_anon_vma() call to the error paths that are missing them.
> 
> This issue showed up during inspection of the error path in vma_merge()
> for an unrelated vma iterator issue.
> 
> Users may experience increased memory usage, which may be problematic as
> the failure would likely be caused by a low memory situation.
> 
> Link: https://lkml.kernel.org/r/20230929183041.2835469-3-Liam.Howlett@oracle.com
> Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree")
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Cc: Jann Horn <jannh@google.com>
> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
> Cc: Suren Baghdasaryan <surenb@google.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
>  mm/mmap.c | 30 ++++++++++++++++++++++--------
>  1 file changed, 22 insertions(+), 8 deletions(-)

All backports now queued up, thanks.

greg k-h