Commit db5c97f0 authored by Li RongQing's avatar Li RongQing Committed by Daniel Borkmann
Browse files

xsk: Fix out of boundary write in __xsk_rcv_memcpy 



first_len is the remainder of the first page we're copying.
If this size is larger, then out of page boundary write will
otherwise happen.

Fixes: c05cd364 ("xsk: add support to allow unaligned chunk placement")
Signed-off-by: default avatarLi RongQing <lirongqing@baidu.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1585813930-19712-1-git-send-email-lirongqing@baidu.com
parent 5222d696

net/xdp/xsk.c

+3 −2
Original line number Diff line number Diff line
@@ -131,8 +131,9 @@ static void __xsk_rcv_memcpy(struct xdp_umem *umem, u64 addr, void *from_buf, 
		u64 page_start = addr & ~(PAGE_SIZE - 1);

		u64 first_len = PAGE_SIZE - (addr - page_start);



		memcpy(to_buf, from_buf, first_len + metalen);

		memcpy(next_pg_addr, from_buf + first_len, len - first_len);

		memcpy(to_buf, from_buf, first_len);

		memcpy(next_pg_addr, from_buf + first_len,

		       len + metalen - first_len);



		return;

	}