Commit c7df4813 authored by Kal Conley's avatar Kal Conley Committed by Daniel Borkmann
Browse files

xsk: Add missing overflow check in xdp_umem_reg 



The number of chunks can overflow u32. Make sure to return -EINVAL on
overflow. Also remove a redundant u32 cast assigning umem->npgs.

Fixes: bbff2f32 ("xsk: new descriptor addressing scheme")
Signed-off-by: default avatarKal Conley <kal.conley@dectris.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20230308174013.1114745-1-kal.conley@dectris.com
parent a33a6eaa

net/xdp/xdp_umem.c

+7 −6
Original line number Diff line number Diff line
@@ -150,10 +150,11 @@ static int xdp_umem_account_pages(struct xdp_umem *umem) 


static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)

{

	u32 npgs_rem, chunk_size = mr->chunk_size, headroom = mr->headroom;

	bool unaligned_chunks = mr->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;

	u64 npgs, addr = mr->addr, size = mr->len;

	unsigned int chunks, chunks_rem;

	u32 chunk_size = mr->chunk_size, headroom = mr->headroom;

	u64 addr = mr->addr, size = mr->len;

	u32 chunks_rem, npgs_rem;

	u64 chunks, npgs;

	int err;



	if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) {
@@ -188,8 +189,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) 
	if (npgs > U32_MAX)

		return -EINVAL;



	chunks = (unsigned int)div_u64_rem(size, chunk_size, &chunks_rem);

	if (chunks == 0)

	chunks = div_u64_rem(size, chunk_size, &chunks_rem);

	if (!chunks || chunks > U32_MAX)

		return -EINVAL;



	if (!unaligned_chunks && chunks_rem)
@@ -202,7 +203,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) 
	umem->headroom = headroom;

	umem->chunk_size = chunk_size;

	umem->chunks = chunks;

	umem->npgs = (u32)npgs;

	umem->npgs = npgs;

	umem->pgs = NULL;

	umem->user = NULL;

	umem->flags = mr->flags;