On Wed, Mar 05, 2025 at 06:27:56PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> The 'err' variable is set in a conditinal branch and is not
> set otherwise:
>
> mm/mremap.c:1017:7: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> 1017 | if (vma->vm_start != old_addr)
>
> Set it to zero before the initial value is set.
>
> Fixes: 3129f7896afb ("mm/mremap: initial refactor of move_vma()")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Thanks for this, however this has already been fixed via Andrew doing a
fix-patch which should land in mm-unstable,-next soon (possibly tmr?).
This is entirely my bad btw, for some reason my compiler locally didn't
catch this even with CONFIG_WERROR on which _really_ surprises me...
> ---
> mm/mremap.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/mm/mremap.c b/mm/mremap.c
> index 456849b9e7bd..9c51a2360d84 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -1014,6 +1014,7 @@ static unsigned long prep_move_vma(struct vma_remap_struct *vrm)
> return -ENOMEM;
>
> if (vma->vm_ops && vma->vm_ops->may_split) {
> + err = 0;
> if (vma->vm_start != old_addr)
> err = vma->vm_ops->may_split(vma, old_addr);
> if (!err && vma->vm_end != old_addr + old_len)
> --
> 2.39.5
>
