linux-user: always translate cmsg when recvmsg

It's possible that a message contains both normal payload and ancillary
data in the same message, and even if no ancillary data is available
this information should be passed to the target, otherwise the target
cmsghdr will be left uninitialized and the target is going to access
uninitialized memory if it expects cmsg.

Always call the function that translate cmsg when recvmsg, because that
function should be empty-cmsg-safe (it creates an empty cmsg in the
target).

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20221028081220.1604244-1-uwu@icenowy.me>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit is contained in:
Icenowy Zheng 2022-10-28 16:12:20 +08:00 committed by Laurent Vivier
parent 8b95210fcb
commit 16c81dd563

View File

@ -3353,7 +3353,8 @@ static abi_long do_sendrecvmsg_locked(int fd, struct target_msghdr *msgp,
if (fd_trans_host_to_target_data(fd)) { if (fd_trans_host_to_target_data(fd)) {
ret = fd_trans_host_to_target_data(fd)(msg.msg_iov->iov_base, ret = fd_trans_host_to_target_data(fd)(msg.msg_iov->iov_base,
MIN(msg.msg_iov->iov_len, len)); MIN(msg.msg_iov->iov_len, len));
} else { }
if (!is_error(ret)) {
ret = host_to_target_cmsg(msgp, &msg); ret = host_to_target_cmsg(msgp, &msg);
} }
if (!is_error(ret)) { if (!is_error(ret)) {