From: Kees Cook Date: Tue, 27 Sep 2022 00:39:27 +0000 (-0700) Subject: w1: Split memcpy() of struct cn_msg flexible array X-Git-Tag: v6.1-rc5~262^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7cd04013fbf3e6dcb67ca6b59aa813269a2ad9ce;p=platform%2Fkernel%2Flinux-starfive.git w1: Split memcpy() of struct cn_msg flexible array To work around a misbehavior of the compiler's ability to see into composite flexible array structs (as detailed in the coming memcpy() hardening series[1]), split the memcpy() of the header and the payload so no false positive run-time overflow warning will be generated. [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org/ Cc: Evgeniy Polyakov Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20220927003927.1942170-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c index fa490aa4..db110cc 100644 --- a/drivers/w1/w1_netlink.c +++ b/drivers/w1/w1_netlink.c @@ -611,7 +611,8 @@ static void w1_cn_callback(struct cn_msg *cn, struct netlink_skb_parms *nsp) } atomic_set(&block->refcnt, 1); block->portid = nsp->portid; - memcpy(&block->request_cn, cn, sizeof(*cn) + cn->len); + block->request_cn = *cn; + memcpy(block->request_cn.data, cn->data, cn->len); node = (struct w1_cb_node *)(block->request_cn.data + cn->len); /* Sneeky, when not bundling, reply_size is the allocated space