On Thu, May 14, 2020 at 11:40:43AM -0500, Brad Love wrote:

Fixes bug exposed by:

[a3fbc2e6bb0: media: mc-entity.c: use WARN_ON, validate link pads]

This patch was merged for v5.8, but should have been merged for v5.7 as well. Please can it be merged into v5.7 stable. The upstream commit is 9f984cacf4f4d53fd8a3f44d7f13528b81c1f6a8.

Thanks,

Sean

The dvbdev incorrectly requests a tuner sink pad to connect to a demux sink pad. The media controller failure percolates back and the dvb device creation fails. Fix this by requesting a tuner source pad. Instead of forcing that pad to be index zero, check if a negative integer error is returned. A note is added that first source pad found is chosen.

Affected bridges cx231xx and em28xx printed the below warning[s] when a variety of media controller dvb enabled devices were connected. The warning returns an error causing all affected devices to fail DVB device creation.

[ 253.138332] ------------[ cut here ]------------ [ 253.138339] WARNING: CPU: 0 PID: 1550 at drivers/media/mc/mc-entity.c:669 media_create_pad_link+0x1e0/0x200 [mc] [ 253.138339] Modules linked in: si2168 em28xx_dvb(+) em28xx si2157 lgdt3306a cx231xx_dvb dvb_core cx231xx_alsa cx25840 cx231xx tveeprom cx2341x i2c_mux videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc ir_rc5_decoder rc_hauppauge mceusb rc_core eda c_mce_amd kvm nls_iso8859_1 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper efi_pstore wmi_bmof k10temp asix usbnet mii nouveau snd_hda_codec_realtek snd_hda_codec_generic input_leds ledtrig_audio snd_hda_codec_hdmi mxm_wmi snd_hda_in tel video snd_intel_dspcfg ttm snd_hda_codec drm_kms_helper snd_hda_core drm snd_hwdep snd_seq_midi snd_seq_midi_event i2c_algo_bit snd_pcm snd_rawmidi fb_sys_fops snd_seq syscopyarea sysfillrect snd_seq_device sysimgblt snd_timer snd soundcore ccp mac_hid sch_fq_codel parport_p c ppdev lp parport ip_tables x_tables autofs4 vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio hid_generic usbhid hid i2c_piix4 ahci libahci wmi gpio_amdpt [ 253.138370] gpio_generic [ 253.138372] CPU: 0 PID: 1550 Comm: modprobe Tainted: G W 5.7.0-rc2+ #181 [ 253.138373] Hardware name: MSI MS-7A39/B350M GAMING PRO (MS-7A39), BIOS 2.G0 04/27/2018 [ 253.138376] RIP: 0010:media_create_pad_link+0x1e0/0x200 [mc] [ 253.138378] Code: 26 fd ff ff 44 8b 4d d0 eb d9 0f 0b 41 b9 ea ff ff ff 44 89 c8 c3 0f 0b 41 b9 ea ff ff ff eb f2 0f 0b 41 b9 ea ff ff ff eb e8 <0f> 0b 41 b9 ea ff ff ff eb af 0f 0b 41 b9 ea ff ff ff eb a5 66 90 [ 253.138379] RSP: 0018:ffffb9ecc0ee7a78 EFLAGS: 00010246 [ 253.138380] RAX: ffff943f706c99d8 RBX: 0000000000000000 RCX: 0000000000000000 [ 253.138381] RDX: ffff943f613e0180 RSI: 0000000000000000 RDI: ffff943f706c9958 [ 253.138381] RBP: ffffb9ecc0ee7ab0 R08: 0000000000000001 R09: ffff943f613e0180 [ 253.138382] R10: ffff943f613e0180 R11: ffff943f706c9400 R12: 0000000000000000 [ 253.138383] R13: 0000000000000001 R14: ffff943f706c9958 R15: 0000000000000001 [ 253.138384] FS: 00007f3cd29ba540(0000) GS:ffff943f8ec00000(0000) knlGS:0000000000000000 [ 253.138385] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 253.138385] CR2: 000055f7de0ca830 CR3: 00000003dd208000 CR4: 00000000003406f0 [ 253.138386] Call Trace: [ 253.138392] media_create_pad_links+0x104/0x1b0 [mc] [ 253.138397] dvb_create_media_graph+0x350/0x5f0 [dvb_core] [ 253.138402] em28xx_dvb_init+0x5ea/0x2600 [em28xx_dvb] [ 253.138408] em28xx_register_extension+0x63/0xc0 [em28xx] [ 253.138410] ? 0xffffffffc039c000 [ 253.138412] em28xx_dvb_register+0x15/0x1000 [em28xx_dvb] [ 253.138416] do_one_initcall+0x71/0x250 [ 253.138418] ? do_init_module+0x27/0x22e [ 253.138421] ? _cond_resched+0x1a/0x50 [ 253.138423] ? kmem_cache_alloc_trace+0x1ec/0x270 [ 253.138425] ? __vunmap+0x1e3/0x240 [ 253.138427] do_init_module+0x5f/0x22e [ 253.138430] load_module+0x2525/0x2d40 [ 253.138436] __do_sys_finit_module+0xe5/0x120 [ 253.138438] ? __do_sys_finit_module+0xe5/0x120 [ 253.138442] __x64_sys_finit_module+0x1a/0x20 [ 253.138443] do_syscall_64+0x57/0x1b0 [ 253.138445] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 253.138446] RIP: 0033:0x7f3cd24dc839 [ 253.138448] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48 [ 253.138449] RSP: 002b:00007ffe4fc514d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 253.138450] RAX: ffffffffffffffda RBX: 000055a9237f63f0 RCX: 00007f3cd24dc839 [ 253.138451] RDX: 0000000000000000 RSI: 000055a922c3ad2e RDI: 0000000000000000 [ 253.138451] RBP: 000055a922c3ad2e R08: 0000000000000000 R09: 0000000000000000 [ 253.138452] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 253.138453] R13: 000055a9237f5550 R14: 0000000000040000 R15: 000055a9237f63f0 [ 253.138456] ---[ end trace a60f19c54aa96ec4 ]---

[ 234.915628] ------------[ cut here ]------------ [ 234.915640] WARNING: CPU: 0 PID: 1502 at drivers/media/mc/mc-entity.c:669 media_create_pad_link+0x1e0/0x200 [mc] [ 234.915641] Modules linked in: si2157 lgdt3306a cx231xx_dvb(+) dvb_core cx231xx_alsa cx25840 cx231xx tveeprom cx2341x i2c_mux videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc ir_rc5_decoder rc_hauppauge mceusb rc_core edac_mce_amd kvm nls_iso8859 _1 crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper efi_pstore wmi_bmof k10temp asix usbnet mii nouveau snd_hda_codec_realtek snd_hda_codec_generic input_leds ledtrig_audio snd_hda_codec_hdmi mxm_wmi snd_hda_intel video snd_intel_dspcf g ttm snd_hda_codec drm_kms_helper snd_hda_core drm snd_hwdep snd_seq_midi snd_seq_midi_event i2c_algo_bit snd_pcm snd_rawmidi fb_sys_fops snd_seq syscopyarea sysfillrect snd_seq_device sysimgblt snd_timer snd soundcore ccp mac_hid sch_fq_codel parport_pc ppdev lp parport ip_tab les x_tables autofs4 vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio hid_generic usbhid hid i2c_piix4 ahci libahci wmi gpio_amdpt gpio_generic [ 234.915700] CPU: 0 PID: 1502 Comm: modprobe Not tainted 5.7.0-rc2+ #181 [ 234.915702] Hardware name: MSI MS-7A39/B350M GAMING PRO (MS-7A39), BIOS 2.G0 04/27/2018 [ 234.915709] RIP: 0010:media_create_pad_link+0x1e0/0x200 [mc] [ 234.915712] Code: 26 fd ff ff 44 8b 4d d0 eb d9 0f 0b 41 b9 ea ff ff ff 44 89 c8 c3 0f 0b 41 b9 ea ff ff ff eb f2 0f 0b 41 b9 ea ff ff ff eb e8 <0f> 0b 41 b9 ea ff ff ff eb af 0f 0b 41 b9 ea ff ff ff eb a5 66 90 [ 234.915714] RSP: 0018:ffffb9ecc1b6fa50 EFLAGS: 00010246 [ 234.915717] RAX: ffff943f8c94a9d8 RBX: 0000000000000000 RCX: 0000000000000000 [ 234.915719] RDX: ffff943f613e0900 RSI: 0000000000000000 RDI: ffff943f8c94a958 [ 234.915721] RBP: ffffb9ecc1b6fa88 R08: 0000000000000001 R09: ffff943f613e0900 [ 234.915723] R10: ffff943f613e0900 R11: ffff943f6b590c00 R12: 0000000000000000 [ 234.915724] R13: 0000000000000001 R14: ffff943f8c94a958 R15: 0000000000000001 [ 234.915727] FS: 00007f4ca3646540(0000) GS:ffff943f8ec00000(0000) knlGS:0000000000000000 [ 234.915729] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 234.915731] CR2: 00007fff7a53ba18 CR3: 00000003da614000 CR4: 00000000003406f0 [ 234.915733] Call Trace: [ 234.915745] media_create_pad_links+0x104/0x1b0 [mc] [ 234.915756] dvb_create_media_graph+0x350/0x5f0 [dvb_core] [ 234.915766] dvb_init.part.4+0x691/0x1360 [cx231xx_dvb] [ 234.915780] dvb_init+0x1a/0x20 [cx231xx_dvb] [ 234.915787] cx231xx_register_extension+0x71/0xa0 [cx231xx] [ 234.915791] ? 0xffffffffc042f000 [ 234.915796] cx231xx_dvb_register+0x15/0x1000 [cx231xx_dvb] [ 234.915802] do_one_initcall+0x71/0x250 [ 234.915807] ? do_init_module+0x27/0x22e [ 234.915811] ? _cond_resched+0x1a/0x50 [ 234.915816] ? kmem_cache_alloc_trace+0x1ec/0x270 [ 234.915820] ? __vunmap+0x1e3/0x240 [ 234.915826] do_init_module+0x5f/0x22e [ 234.915831] load_module+0x2525/0x2d40 [ 234.915848] __do_sys_finit_module+0xe5/0x120 [ 234.915850] ? __do_sys_finit_module+0xe5/0x120 [ 234.915862] __x64_sys_finit_module+0x1a/0x20 [ 234.915865] do_syscall_64+0x57/0x1b0 [ 234.915870] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 234.915872] RIP: 0033:0x7f4ca3168839 [ 234.915876] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48 [ 234.915878] RSP: 002b:00007ffcea3db3b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 234.915881] RAX: ffffffffffffffda RBX: 000055af22c29340 RCX: 00007f4ca3168839 [ 234.915882] RDX: 0000000000000000 RSI: 000055af22c38390 RDI: 0000000000000001 [ 234.915884] RBP: 000055af22c38390 R08: 0000000000000000 R09: 0000000000000000 [ 234.915885] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 [ 234.915887] R13: 000055af22c29060 R14: 0000000000040000 R15: 0000000000000000 [ 234.915896] ---[ end trace a60f19c54aa96ec3 ]---

Signed-off-by: Brad Love brad@nextdimension.cc

drivers/media/dvb-core/dvbdev.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c index 80b6a71aa33e..1cd2dc7e4168 100644 --- a/drivers/media/dvb-core/dvbdev.c +++ b/drivers/media/dvb-core/dvbdev.c @@ -707,9 +707,10 @@ int dvb_create_media_graph(struct dvb_adapter *adap, } if (ntuner && ndemod) {

• pad_source = media_get_pad_index(tuner, true,
  

• /* NOTE: first found tuner source pad presumed correct */
  

• pad_source = media_get_pad_index(tuner, false,
  			 PAD_SIGNAL_ANALOG);
  

• if (pad_source)
  

• if (pad_source < 0)
  return -EINVAL;
  

  ret = media_create_pad_links(mdev, MEDIA_ENT_F_TUNER,

-- 2.23.0