QNetworkInterface/Linux: fix mismatch of pointer and pointee

It was hard to see the problem because of the lambda, combined with
reinterpret_cast on the output of non-typesafe C macro. NLMSG_DATA
returns a void*, so use static_cast to be sure not to do something
wrong.

This only affected the code that dealt with unexpected replies from the
Linux kernel, which it doesn't send. So I don't expect this fixes any
improper QNetworkInterface behavior.

Found by CodeChecker.

Change-Id: I61b74deaf2514644a24efffd1770d75e5a4f2636
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit 5bcacdbd1aa237cb3d39ffafbe378688a00ea502)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
This commit is contained in:
Thiago Macieira 2023-07-11 07:44:20 -07:00 committed by Qt Cherry-pick Bot
parent ae6e27d601
commit 8d86ae9f90

View File

@ -111,7 +111,10 @@ struct NetlinkSocket
template <typename Lambda> struct ProcessNetlinkRequest
{
using FunctionTraits = QtPrivate::FunctionPointer<decltype(&Lambda::operator())>;
using FirstArgument = typename FunctionTraits::Arguments::Car;
using FirstArgumentPointer = typename FunctionTraits::Arguments::Car;
using FirstArgument = std::remove_pointer_t<FirstArgumentPointer>;
static_assert(std::is_pointer_v<FirstArgumentPointer>);
static_assert(std::is_aggregate_v<FirstArgument>);
static int expectedTypeForRequest(int rtype)
{
@ -136,7 +139,7 @@ template <typename Lambda> struct ProcessNetlinkRequest
if (!NLMSG_OK(hdr, quint32(len)))
return;
auto arg = reinterpret_cast<FirstArgument>(NLMSG_DATA(hdr));
auto arg = static_cast<FirstArgument *>(NLMSG_DATA(hdr));
size_t payloadLen = NLMSG_PAYLOAD(hdr, 0);
// is this a multipart message?
@ -156,7 +159,7 @@ template <typename Lambda> struct ProcessNetlinkRequest
// NLMSG_NEXT also updates the len variable
hdr = NLMSG_NEXT(hdr, len);
arg = reinterpret_cast<FirstArgument>(NLMSG_DATA(hdr));
arg = static_cast<FirstArgument *>(NLMSG_DATA(hdr));
payloadLen = NLMSG_PAYLOAD(hdr, 0);
} while (NLMSG_OK(hdr, quint32(len)));