On Tue, 13 Oct 2020 17:26:28 +0200, Kai Vehmanen wrote:
A race exists between closing a PCM and update of ELD data. In hdmi_pcm_close(), hinfo->nid value is modified without taking spec->pcm_lock. If this happens concurrently while processing an ELD update in hdmi_pcm_setup_pin(), converter assignment may be done incorrectly.
This bug was found by hitting a WARN_ON in snd_hda_spdif_ctls_assign() in a HDMI receiver connection stress test:
[2739.684569] WARNING: CPU: 5 PID: 2090 at sound/pci/hda/patch_hdmi.c:1898 check_non_pcm_per_cvt+0x41/0x50 [snd_hda_codec_hdmi] ... [2739.684707] Call Trace: [2739.684720] update_eld+0x121/0x5a0 [snd_hda_codec_hdmi] [2739.684736] hdmi_present_sense+0x21e/0x3b0 [snd_hda_codec_hdmi] [2739.684750] check_presence_and_report+0x81/0xd0 [snd_hda_codec_hdmi] [2739.684842] intel_audio_codec_enable+0x122/0x190 [i915]
Fixes: 42b2987079ec ("ALSA: hda - hdmi playback without monitor in dynamic pcm bind mode") Signed-off-by: Kai Vehmanen kai.vehmanen@linux.intel.com
Applied now. Thanks.
Takashi