[ Upstream commit c6a502c2299941c8326d029cfc8a3bc8a4607ad5 ] dsp_pipeline_build() allocates dup pointer by kstrdup(cfg), but then it updates dup variable by strsep(&dup, "|"). As a result when it calls kfree(dup), the dup variable contains NULL. Found by Linux Driver Verification project (linuxtesting.org) with SVACE. Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Fixes: 960366cf8dbb ("Add mISDN DSP") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>