linux

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Tom Rix 3fbbf2148a soundwire: fix double free of dangling pointer

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.

Fixes: 99b8a5d608a6 ("soundwire: Add bank switch routine")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200902202650.14189-1-trix@redhat.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

2020-09-03 14:10:19 +05:30

bus_type.c

soundwire: extend SDW_SLAVE_ENTRY

2020-06-30 21:26:17 +05:30

bus.c

soundwire: bus: fix typo in comment on INTSTAT registers

2020-08-19 14:39:05 +05:30

bus.h

soundwire: add Slave sysfs support

2020-05-20 17:22:41 +05:30

cadence_master.c

soundwire: intel/cadence: merge Soundwire interrupt handlers/threads