On 02-09-20, 13:26, trix@xxxxxxxxxx wrote:
> From: Tom Rix <trix@xxxxxxxxxx>
>
> clang static analysis flags this problem
>
> stream.c:844:9: warning: Use of memory after
> it is freed
> kfree(bus->defer_msg.msg->buf);
> ^~~~~~~~~~~~~~~~~~~~~~~
>
> This happens in an error handler cleaning up memory
> allocated for elements in a list.
>
> list_for_each_entry(m_rt, &stream->master_list, stream_node) {
> bus = m_rt->bus;
>
> kfree(bus->defer_msg.msg->buf);
> kfree(bus->defer_msg.msg);
> }
>
> And is triggered when the call to sdw_bank_switch() fails.
> There are a two problems.
>
> First, when sdw_bank_switch() fails, though it frees memory it
> does not clear bus's reference 'defer_msg.msg' to that memory.
>
> The second problem is the freeing msg->buf. In some cases
> msg will be NULL so this will dereference a null pointer.
> Need to check before freeing.
Applied, thanks
--
~Vinod
