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authorJakub Kicinski <kuba@kernel.org>2022-11-17 19:39:03 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-10-10 22:00:46 +0200
commitff81d1c77d0890b0cf835378614ba6df02de6cd8 (patch)
tree3a1dea871caafa8764139658f771405d2d108af9
parent6cd57f5c779578c2c41f6ab3dedd71aaddca4d9f (diff)
netlink: remove the flex array from struct nlmsghdr
commit c73a72f4cbb47672c8cc7f7d7aba52f1cb15baca upstream. I've added a flex array to struct nlmsghdr in commit 738136a0e375 ("netlink: split up copies in the ack construction") to allow accessing the data easily. It leads to warnings with clang, if user space wraps this structure into another struct and the flex array is not at the end of the container. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/all/20221114023927.GA685@u2004-local/ Link: https://lore.kernel.org/r/20221118033903.1651026-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--include/uapi/linux/netlink.h2
-rw-r--r--net/netlink/af_netlink.c2
2 files changed, 1 insertions, 3 deletions
diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index 5da0da59bf010..e2ae82e3f9f71 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -48,7 +48,6 @@ struct sockaddr_nl {
* @nlmsg_flags: Additional flags
* @nlmsg_seq: Sequence number
* @nlmsg_pid: Sending process port ID
- * @nlmsg_data: Message payload
*/
struct nlmsghdr {
__u32 nlmsg_len;
@@ -56,7 +55,6 @@ struct nlmsghdr {
__u16 nlmsg_flags;
__u32 nlmsg_seq;
__u32 nlmsg_pid;
- __u8 nlmsg_data[];
};
/* Flags values */
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a572a30dfd98d..cb833302270a6 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2458,7 +2458,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
if (!nlmsg_append(skb, nlmsg_len(nlh)))
goto err_bad_put;
- memcpy(errmsg->msg.nlmsg_data, nlh->nlmsg_data,
+ memcpy(nlmsg_data(&errmsg->msg), nlmsg_data(nlh),
nlmsg_len(nlh));
}