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authorKal Conley <kal.conley@dectris.com>2023-03-08 18:40:13 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-30 12:49:02 +0200
commita069909acc4435eeb41d05ccc03baa447cc01b7e (patch)
treec5beaa6e5883bdf43f34a1a443c21f274d6b688c /net
parent4797ad1f561797f91fb2064739937cb76287e613 (diff)
downloadlinux-a069909acc4435eeb41d05ccc03baa447cc01b7e.tar.gz
xsk: Add missing overflow check in xdp_umem_reg
[ 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>
Diffstat (limited to 'net')
-rw-r--r--net/xdp/xdp_umem.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 4681e8e8ad94..02207e852d79 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -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;