From: Kal Conley <kal.conley@xxxxxxxxxxx>
[ 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@xxxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
Link: https://lore.kernel.org/bpf/20230308174013.1114745-1-kal.conley@xxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 f01ef6bda3909..65f918d29531d 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -152,10 +152,11 @@ 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) {
@@ -190,8 +191,8 @@ 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)
@@ -204,7 +205,7 @@ 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;
--
2.39.2
