xsk: fix an integer overflow in xp_create_and_assign_umem()

jira LE-3262
cve CVE-2025-21997
Rebuild_History Non-Buildable kernel-5.14.0-570.21.1.el9_6
commit-author Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
commit 559847f

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: 94033cd ("xsk: Optimize for aligned case")
	Cc: stable@vger.kernel.org
	Signed-off-by: Ilia Gavrilov <Ilia.Gavrilov@infotecs.ru>
Link: https://patch.msgid.link/20250313085007.3116044-1-Ilia.Gavrilov@infotecs.ru
	Signed-off-by: Paolo Abeni <pabeni@redhat.com>

(cherry picked from commit 559847f)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

Author: PlaidCat

net/xdp/xsk_buff_pool.c

@@ -106,7 +106,7 @@ 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;