Messages in this thread Patch in this message | | | Date | Tue, 13 Jan 2015 15:16:10 +0000 | From | Qais Yousef <> | Subject | Re: [PATCH v2] ALSA: ASoC: soc-compress.c: fix NULL dereference |
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On 01/13/2015 02:59 PM, Vinod Koul wrote: > On Tue, Jan 13, 2015 at 11:18:53AM +0000, Qais Yousef wrote: >> In soc_new_compress() when rtd->dai_link->daynmic is set, we create the pcm > ^^^^^^^^ > typo >> substreams with this call: >> >> ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num, >> 1, 0, &be_pcm); >> >> which passes 0 as capture_count leading to >> >> be_pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream >> >> being NULL, hence when trying to set rtd a few lines below we get an oops. > It is a good practice to add the oops here
Will this really be helpful? I think it'll be more clutter (the backtrace on metag arch is not great):
Oops: err 8007 (Unknown fault) addr 00000008 [#1] Modules linked in: CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 3.18.0-rc4+ #1904 Workqueue: deferwq _deferred_probe_work_func task: 4f030780 ti: 4f044000 task.ti: 4f044000 pt_regs @ 4f044388 SaveMask = 0x4041 Flags = 0x0008 (Znoc) TXRPT = 0x00000000 PC = 0x402e6c58 A0StP = 0x4f044388 A1GbP = 0x60001000 A0FrP = 0x4f044110 A1LbP = 0x40000048 A0.2 = 0x00000000 A1.2 = 0x00000000 A0.3 = 0x40090000 A1.3 = 0x00000001 D0Re0 = 0x00000000 D1Re0 = 0x00000001 D0Ar6 = 0x00000000 D1Ar5 = 0x4b5c1a00 D0Ar4 = 0x4f044330 D1Ar3 = 0x405833a8 D0Ar2 = 0x4f1d7170 D1Ar1 = 0x4b5c25a0 D0FrT = 0x00000001 D1RtP = 0x402e6c20 D0.5 = 0x00000000 D1.5 = 0x4f1f65c4 D0.6 = 0x4f1f65c4 D1.6 = 0x4f1d0500 D0.7 = 0x00000001 D1.7 = 0x4f1e3e40
Call trace: [<40410004>] _ieee80211_change_bss+0x1b4/0x220 [<400f8034>] _kernfs_add_one+0x10c/0x17c [<400fa2b0>] ___kernfs_create_file+0x94/0xdc [<402d8bf0>] _snd_soc_register_card+0x12b8/0x1380 [<400170e8>] ___request_region+0x58/0x150 [<402068b4>] _devres_add+0x14/0x2c [<402e97f0>] _zero1xx_probe+0x2b8/0x37c [<40205004>] _platform_drv_probe+0x4c/0xc0 [<40204fb4>] _platform_drv_remove+0x3c/0x40 [<402032e0>] _driver_probe_device+0xc8/0x294 [<40204fb4>] _platform_drv_remove+0x3c/0x40 [<40203624>] _wait_for_device_probe+0x7c/0x80 [<40201cac>] _bus_for_each_drv+0x5c/0xb0 [<40203708>] _device_attach+0x84/0x9c [<40202258>] _bus_probe_device+0x90/0xd0 [<4020354c>] _deferred_probe_work_func+0x70/0xac [<40025d84>] _process_one_work+0x110/0x364 [<402034d8>] _device_bind_driver+0x2c/0x30 [<40046150>] _mod_timer+0xc4/0x178 [<400286a4>] _worker_thread+0x14c/0x4d4 [<4002b90c>] _kthread_parkme+0x14/0x18 [<40028554>] _pool_mayday_timeout+0xe8/0xec [<4002ba08>] _kthread+0xf8/0x100 [<4000aeb4>] _ret_from_fork+0x44/0x110 [<4002b90c>] _kthread_parkme+0x14/0x18 [<40000044>] _text+0x44/0x48 [<40000044>] _text+0x44/0x48 [<4002b90c>] _kthread_parkme+0x14/0x18
Process: kworker/u2:0 (pid: 6, stack limit = 4f046000) ---[ end trace fabdbb359f5c60d8 ]---
> >> Fix by using rtd->dai_link->dpcm_playback and rtd->dai_link->dpcm_capture as >> playback_count and capture_count to snd_pcm_new_internal(). >> >> Signed-off-by: Qais Yousef <qais.yousef@imgtec.com> >> Cc: Vinod Koul <vinod.koul@intel.com> >> Cc: Liam Girdwood <lgirdwood@gmail.com> >> Cc: Mark Brown <broonie@kernel.org> >> Cc: Jaroslav Kysela <perex@perex.cz> >> Cc: Takashi Iwai <tiwai@suse.de> >> Cc: linux-kernel@vger.kernel.org >> --- >> v2->v1: >> - use better way to fix it than just removing the line that caused the oops >> >> sound/soc/soc-compress.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c >> index 590a82f01d0b..27a668463ad7 100644 >> --- a/sound/soc/soc-compress.c >> +++ b/sound/soc/soc-compress.c >> @@ -659,7 +659,8 @@ int soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num) >> rtd->dai_link->stream_name); >> >> ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num, >> - 1, 0, &be_pcm); >> + rtd->dai_link->dpcm_playback, >> + rtd->dai_link->dpcm_capture, &be_pcm); >> if (ret < 0) { >> dev_err(rtd->card->dev, "ASoC: can't create compressed for %s\n", >> rtd->dai_link->name); >> @@ -668,8 +669,10 @@ int soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num) >> >> rtd->pcm = be_pcm; >> rtd->fe_compr = 1; >> - be_pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd; >> - be_pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->private_data = rtd; >> + if (rtd->dai_link->dpcm_playback) >> + be_pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd; >> + if (rtd->dai_link->dpcm_capture) > this should be else if, as for compressed device we can have playback or > capture not both > >> + be_pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->private_data = rtd; >> memcpy(compr->ops, &soc_compr_dyn_ops, sizeof(soc_compr_dyn_ops)); >> } else >> memcpy(compr->ops, &soc_compr_ops, sizeof(soc_compr_ops)); >> -- >> 2.1.0 >>
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