From: Takashi Iwai Date: Mon, 5 May 2014 14:20:05 +0000 (-0300) Subject: media: ivtv: Fix Oops when no firmware is loaded X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e48fee81d3ea8bc59d8fa8020fcd8077d3e12fe8;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git media: ivtv: Fix Oops when no firmware is loaded commit deb29e90221a6d4417aa67be971613c353180331 upstream. When ivtv PCM device is accessed at the state where no firmware is loaded, it oopses like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000050 IP: [] try_mailbox.isra.0+0x11/0x50 [ivtv] Call Trace: [] ivtv_api_call+0x160/0x6b0 [ivtv] [] ivtv_api+0x16/0x40 [ivtv] [] ivtv_vapi+0xac/0xc0 [ivtv] [] ivtv_start_v4l2_encode_stream+0x19d/0x630 [ivtv] [] snd_ivtv_pcm_capture_open+0x173/0x1c0 [ivtv_alsa] [] snd_pcm_open_substream+0x51/0x100 [snd_pcm] [] snd_pcm_open+0xb3/0x260 [snd_pcm] [] snd_pcm_capture_open+0x37/0x50 [snd_pcm] [] snd_open+0xa7/0x1e0 [snd] [] chrdev_open+0x88/0x1d0 [] do_dentry_open+0x1de/0x270 [] do_last+0x1c3/0xec0 [] path_openat+0xb6/0x670 [] do_filp_open+0x35/0x80 [] do_sys_open+0x129/0x210 [] system_call_fastpath+0x1a/0x1f This patch adds the check of firmware at PCM open callback like other open callbacks of this driver. Bugzilla: https://apibugzilla.novell.com/show_bug.cgi?id=875440 Signed-off-by: Takashi Iwai Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/media/pci/ivtv/ivtv-alsa-pcm.c b/drivers/media/pci/ivtv/ivtv-alsa-pcm.c index e1863dbf4edc..7a9b98bc208b 100644 --- a/drivers/media/pci/ivtv/ivtv-alsa-pcm.c +++ b/drivers/media/pci/ivtv/ivtv-alsa-pcm.c @@ -159,6 +159,12 @@ static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream) /* Instruct the CX2341[56] to start sending packets */ snd_ivtv_lock(itvsc); + + if (ivtv_init_on_first_open(itv)) { + snd_ivtv_unlock(itvsc); + return -ENXIO; + } + s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM]; v4l2_fh_init(&item.fh, s->vdev);