Re: [PATCH v2] tee: shm: don't warn on oversized request in tee_dyn_shm_alloc_helper()

[Jens Wiklander]

On Mon, Oct 26, 2026 at 4:04 PM Georgiy Osokin <g.osokin@xxxxxxxxxxxx> wrote:
>
> tee_dyn_shm_alloc_helper() passes the size from TEE_IOC_SHM_ALLOC to
> alloc_pages_exact(), which needs one physically contiguous block. A size
> above 4 MiB (MAX_PAGE_ORDER with 4 KiB pages) is more than the page
> allocator can serve, so it trips its order warning; on a panic_on_warn
> kernel that is a panic.
>
> The size comes from userspace and the request fails with -ENOMEM anyway,
> so pass __GFP_NOWARN.
>
> Fixes: abd135ba215c ("tee: optee: add optee-specific shared pool implementation")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: lvc-project@xxxxxxxxxxxxxxxx
> Signed-off-by: Georgiy Osokin <g.osokin@xxxxxxxxxxxx>
> ---
> v2: Fixes now points to abd135ba215c, the commit that introduced the
>     unchecked allocation; cf4441503e20 only moved the code.
> v1: https://lore.kernel.org/all/20261026105209.161195-1-g.osokin@xxxxxxxxxxxx/
>
>  drivers/tee/tee_shm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index daa4af1..8b117d6 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -352,7 +352,7 @@ int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
>          * and there's no need for any larger alignment.
>          */
>         shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE,
> -                                      GFP_KERNEL | __GFP_ZERO);
> +                                      GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
>         if (!shm->kaddr)
>                 return -ENOMEM;
>
> --
> 2.54.0
>

I missed this one, confusing it with the other "don't warn" patch.
Looks good. Sumit, do you agree?

Cheers,
Jens