xsk: Add missing overflow check in xdp_umem_reg

[ Upstream commit c7df4813b1 ]

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

Fixes: bbff2f321a ("xsk: new descriptor addressing scheme")
Signed-off-by: Kal Conley <kal.conley@dectris.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20230308174013.1114745-1-kal.conley@dectris.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kal Conley 2023-03-08 18:40:13 +01:00 committed by Greg Kroah-Hartman
parent 4797ad1f56
commit a069909acc
1 changed files with 7 additions and 6 deletions

View File

@ -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;