diff options
| author | Tom Rix <trix@redhat.com> | 2020-09-02 23:26:50 +0300 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-09-03 11:40:19 +0300 |
| commit | 3fbbf2148a406b3e350fe91e6fdd78eb42ecad24 (patch) | |
| tree | 79cb08c99781796ffd76a1b38c86da4f57d5d258 /drivers/soundwire | |
| parent | f8d0168e035f6359275efcfd1ad014c80e5adaa9 (diff) | |
| download | linux-3fbbf2148a406b3e350fe91e6fdd78eb42ecad24.tar.xz | |
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>
Diffstat (limited to 'drivers/soundwire')
| -rw-r--r-- | drivers/soundwire/stream.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c index 37290a799023..6e36deb505b1 100644 --- a/drivers/soundwire/stream.c +++ b/drivers/soundwire/stream.c @@ -717,6 +717,7 @@ error: kfree(wbuf); error_1: kfree(wr_msg); + bus->defer_msg.msg = NULL; return ret; } @@ -840,9 +841,10 @@ static int do_bank_switch(struct sdw_stream_runtime *stream) error: 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); + if (bus->defer_msg.msg) { + kfree(bus->defer_msg.msg->buf); + kfree(bus->defer_msg.msg); + } } msg_unlock: |