Re: [PATCH] net: fix buffer overflow in af_xdp_umem_create()

[Jason Wang]

On Mon, Jun 2, 2025 at 4:57 PM Anastasia Belova <nabelov...@gmail.com> wrote:
>
> s->pool has n_descs elements so maximum i should be
> n_descs - 1. Fix the upper bound.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: cb039ef3d9 ("net: add initial support for AF_XDP network backend")
> Signed-off-by: Anastasia Belova <nabelov...@gmail.com>
> ---
>  net/af-xdp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/af-xdp.c b/net/af-xdp.c
> index 01c5fb914e..d022534d76 100644
> --- a/net/af-xdp.c
> +++ b/net/af-xdp.c
> @@ -323,7 +323,7 @@ static int af_xdp_umem_create(AFXDPState *s, int sock_fd, 
> Error **errp)
>
>      s->pool = g_new(uint64_t, n_descs);
>      /* Fill the pool in the opposite order, because it's a LIFO queue. */
> -    for (i = n_descs; i >= 0; i--) {
> +    for (i = n_descs - 1; i >= 0; i--) {
>          s->pool[i] = i * XSK_UMEM__DEFAULT_FRAME_SIZE;
>      }
>      s->n_pool = n_descs;
> --
> 2.47.0
>

Queued.

Thanks