From: Kal Conley kal.conley@dectris.com
[ Upstream commit c7df4813b149362248d6ef7be41a311e27bf75fe ]
The number of chunks can overflow u32. Make sure to return -EINVAL on overflow. Also remove a redundant u32 cast assigning umem->npgs.
Fixes: bbff2f321a86 ("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 --- net/xdp/xdp_umem.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 56a28a686988d..42b19feb2b6e5 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -153,10 +153,11 @@ 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) { @@ -191,8 +192,8 @@ 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) @@ -205,7 +206,7 @@ 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;