[lvc-project] [PATCH net] xsk: fix an integer overflow in xp_create_and_assign_umem()

[Gavrilov Ilia]

Since the i and pool->chunk_size variables are of type 'u32',
their product can wrap around and then be cast to 'u64'.
This can lead to two different XDP buffers pointing to the same
memory area.

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.

Fixes: 94033cd8e73b ("xsk: Optimize for aligned case")
Cc: stable at vger.kernel.org
Signed-off-by: Ilia Gavrilov <Ilia.Gavrilov at infotecs.ru>
---
 net/xdp/xsk_buff_pool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 1f7975b49657..d158cb6dd391 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -105,7 +105,7 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 		if (pool->unaligned)
 			pool->free_heads[i] = xskb;
 		else
-			xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
+			xp_init_xskb_addr(xskb, pool, (u64)i * pool->chunk_size);
 	}
 
 	return pool;
-- 
2.39.5