The size of devnode_nums[] bit array is too short to store information for VFL_TYPE_TOUCH. That causes it to override other memory regions.
Thankfully, on recent reports, it is overriding video_device[] array, trigging a WARN_ON(). Yet, it just warns about the problem, but let the code excecuting, with generates an OOPS:
[ 43.177394] WARNING: CPU: 1 PID: 711 at drivers/media/v4l2-core/v4l2-dev.c:945 __video_register_device+0xc99/0x1090 [videodev] [ 43.177396] Modules linked in: hid_sensor_custom hid_sensor_als hid_sensor_incl_3d hid_sensor_rotation hid_sensor_magn_3d hid_sensor_accel_3d hid_sensor_gyro_3d hid_sensor_trigger industrialio_triggered_buffer kfifo_buf joydev hid_sensor_iio_common hid_rmi(+) rmi_core industrialio videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev hid_multitouch media hid_sensor_hub binfmt_misc nls_iso8859_1 snd_hda_codec_hdmi arc4 snd_soc_skl snd_soc_skl_ipc snd_hda_ext_core snd_soc_sst_dsp snd_soc_sst_ipc snd_hda_codec_realtek snd_soc_acpi snd_hda_codec_generic snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine snd_hda_intel snd_hda_codec intel_rapl snd_hda_core x86_pkg_temp_thermal snd_hwdep intel_powerclamp coretemp snd_pcm kvm_intel snd_seq_midi snd_seq_midi_event snd_rawmidi crct10dif_pclmul [ 43.177426] crc32_pclmul ghash_clmulni_intel iwlmvm pcbc mac80211 snd_seq aesni_intel iwlwifi aes_x86_64 snd_seq_device crypto_simd glue_helper cryptd snd_timer intel_cstate intel_rapl_perf input_leds serio_raw intel_wmi_thunderbolt snd wmi_bmof cfg80211 soundcore ideapad_laptop sparse_keymap idma64 virt_dma tpm_crb acpi_pad int3400_thermal acpi_thermal_rel intel_pch_thermal processor_thermal_device mac_hid int340x_thermal_zone mei_me intel_soc_dts_iosf mei intel_lpss_pci shpchp intel_lpss sch_fq_codel vfio_pci nfsd vfio_virqfd parport_pc ppdev auth_rpcgss nfs_acl lockd grace lp parport sunrpc ip_tables x_tables autofs4 hid_logitech_hidpp hid_logitech_dj hid_generic usbhid kvmgt vfio_mdev mdev vfio_iommu_type1 vfio kvm irqbypass i915 i2c_algo_bit drm_kms_helper syscopyarea sdhci_pci sysfillrect [ 43.177466] sysimgblt cqhci fb_sys_fops sdhci drm i2c_hid wmi hid video pinctrl_sunrisepoint pinctrl_intel [ 43.177474] CPU: 1 PID: 711 Comm: systemd-udevd Not tainted 4.16.0 #1 [ 43.177475] Hardware name: LENOVO 80UE/VIUU4, BIOS 2UCN10T 10/14/2016 [ 43.177481] RIP: 0010:__video_register_device+0xc99/0x1090 [videodev] [ 43.177482] RSP: 0000:ffffa5c5c231b420 EFLAGS: 00010202 [ 43.177484] RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000000000 [ 43.177485] RDX: ffffffffc0c44cc0 RSI: ffffffffffffffff RDI: ffffffffc0c44cc0 [ 43.177486] RBP: ffffa5c5c231b478 R08: ffffffffc0c96900 R09: ffff8eda1a51f018 [ 43.177487] R10: 0000000000000600 R11: 00000000000003b6 R12: 0000000000000000 [ 43.177488] R13: 0000000000000005 R14: ffffffffc0c96900 R15: ffff8eda1d6d91c0 [ 43.177489] FS: 00007fd2d8ef2480(0000) GS:ffff8eda33480000(0000) knlGS:0000000000000000 [ 43.177490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 43.177491] CR2: 00007ffe0a6ad01c CR3: 0000000456ae2004 CR4: 00000000003606e0 [ 43.177492] Call Trace: [ 43.177498] ? devres_add+0x5f/0x70 [ 43.177502] rmi_f54_probe+0x437/0x470 [rmi_core] [ 43.177505] rmi_function_probe+0x25/0x30 [rmi_core] [ 43.177507] driver_probe_device+0x310/0x480 [ 43.177509] __device_attach_driver+0x86/0x100 [ 43.177511] ? __driver_attach+0xf0/0xf0 [ 43.177512] bus_for_each_drv+0x6b/0xb0 [ 43.177514] __device_attach+0xdd/0x160 [ 43.177516] device_initial_probe+0x13/0x20 [ 43.177518] bus_probe_device+0x95/0xa0 [ 43.177519] device_add+0x44b/0x680 [ 43.177522] rmi_register_function+0x62/0xd0 [rmi_core] [ 43.177525] rmi_create_function+0x112/0x1a0 [rmi_core] [ 43.177527] ? rmi_driver_clear_irq_bits+0xc0/0xc0 [rmi_core] [ 43.177530] rmi_scan_pdt+0xca/0x1a0 [rmi_core] [ 43.177535] rmi_init_functions+0x5b/0x120 [rmi_core] [ 43.177537] rmi_driver_probe+0x152/0x3c0 [rmi_core] [ 43.177547] ? sysfs_create_link+0x25/0x40 [ 43.177549] driver_probe_device+0x310/0x480 [ 43.177551] __device_attach_driver+0x86/0x100 [ 43.177553] ? __driver_attach+0xf0/0xf0 [ 43.177554] bus_for_each_drv+0x6b/0xb0 [ 43.177556] __device_attach+0xdd/0x160 [ 43.177558] device_initial_probe+0x13/0x20 [ 43.177560] bus_probe_device+0x95/0xa0 [ 43.177561] device_add+0x44b/0x680 [ 43.177564] rmi_register_transport_device+0x84/0x100 [rmi_core] [ 43.177568] rmi_input_configured+0xbf/0x1a0 [hid_rmi] [ 43.177571] ? input_allocate_device+0xdf/0xf0 [ 43.177574] hidinput_connect+0x4a9/0x37a0 [hid] [ 43.177578] hid_connect+0x326/0x3d0 [hid] [ 43.177581] hid_hw_start+0x42/0x70 [hid] [ 43.177583] rmi_probe+0x115/0x510 [hid_rmi] [ 43.177586] hid_device_probe+0xd3/0x150 [hid] [ 43.177588] ? sysfs_create_link+0x25/0x40 [ 43.177590] driver_probe_device+0x310/0x480 [ 43.177592] __driver_attach+0xbf/0xf0 [ 43.177593] ? driver_probe_device+0x480/0x480 [ 43.177595] bus_for_each_dev+0x74/0xb0 [ 43.177597] ? kmem_cache_alloc_trace+0x1a6/0x1c0 [ 43.177599] driver_attach+0x1e/0x20 [ 43.177600] bus_add_driver+0x167/0x260 [ 43.177602] ? 0xffffffffc0cbc000 [ 43.177604] driver_register+0x60/0xe0 [ 43.177605] ? 0xffffffffc0cbc000 [ 43.177607] __hid_register_driver+0x63/0x70 [hid] [ 43.177610] rmi_driver_init+0x23/0x1000 [hid_rmi] [ 43.177612] do_one_initcall+0x52/0x191 [ 43.177615] ? _cond_resched+0x19/0x40 [ 43.177617] ? kmem_cache_alloc_trace+0xa2/0x1c0 [ 43.177619] ? do_init_module+0x27/0x209 [ 43.177621] do_init_module+0x5f/0x209 [ 43.177623] load_module+0x1987/0x1f10 [ 43.177626] ? ima_post_read_file+0x96/0xa0 [ 43.177629] SYSC_finit_module+0xfc/0x120 [ 43.177630] ? SYSC_finit_module+0xfc/0x120 [ 43.177632] SyS_finit_module+0xe/0x10 [ 43.177634] do_syscall_64+0x73/0x130 [ 43.177637] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 43.177638] RIP: 0033:0x7fd2d880b839 [ 43.177639] RSP: 002b:00007ffe0a6b2368 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 43.177641] RAX: ffffffffffffffda RBX: 000055cdd86542e0 RCX: 00007fd2d880b839 [ 43.177641] RDX: 0000000000000000 RSI: 00007fd2d84ea0e5 RDI: 0000000000000016 [ 43.177642] RBP: 00007fd2d84ea0e5 R08: 0000000000000000 R09: 00007ffe0a6b2480 [ 43.177643] R10: 0000000000000016 R11: 0000000000000246 R12: 0000000000000000 [ 43.177644] R13: 000055cdd8688930 R14: 0000000000020000 R15: 000055cdd86542e0 [ 43.177645] Code: 48 c7 c7 54 b4 c3 c0 e8 96 9d ec dd e9 d4 fb ff ff 0f 0b 41 be ea ff ff ff e9 c7 fb ff ff 0f 0b 41 be ea ff ff ff e9 ba fb ff ff <0f> 0b e9 d8 f4 ff ff 83 fa 01 0f 84 c4 02 00 00 48 83 78 68 00 [ 43.177675] ---[ end trace d44d9bc41477c2dd ]--- [ 43.177679] BUG: unable to handle kernel NULL pointer dereference at 0000000000000499 [ 43.177723] IP: __video_register_device+0x1cc/0x1090 [videodev] [ 43.177749] PGD 0 P4D 0 [ 43.177764] Oops: 0000 [#1] SMP PTI [ 43.177780] Modules linked in: hid_sensor_custom hid_sensor_als hid_sensor_incl_3d hid_sensor_rotation hid_sensor_magn_3d hid_sensor_accel_3d hid_sensor_gyro_3d hid_sensor_trigger industrialio_triggered_buffer kfifo_buf joydev hid_sensor_iio_common hid_rmi(+) rmi_core industrialio videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev hid_multitouch media hid_sensor_hub binfmt_misc nls_iso8859_1 snd_hda_codec_hdmi arc4 snd_soc_skl snd_soc_skl_ipc snd_hda_ext_core snd_soc_sst_dsp snd_soc_sst_ipc snd_hda_codec_realtek snd_soc_acpi snd_hda_codec_generic snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine snd_hda_intel snd_hda_codec intel_rapl snd_hda_core x86_pkg_temp_thermal snd_hwdep intel_powerclamp coretemp snd_pcm kvm_intel snd_seq_midi snd_seq_midi_event snd_rawmidi crct10dif_pclmul [ 43.178055] crc32_pclmul ghash_clmulni_intel iwlmvm pcbc mac80211 snd_seq aesni_intel iwlwifi aes_x86_64 snd_seq_device crypto_simd glue_helper cryptd snd_timer intel_cstate intel_rapl_perf input_leds serio_raw intel_wmi_thunderbolt snd wmi_bmof cfg80211 soundcore ideapad_laptop sparse_keymap idma64 virt_dma tpm_crb acpi_pad int3400_thermal acpi_thermal_rel intel_pch_thermal processor_thermal_device mac_hid int340x_thermal_zone mei_me intel_soc_dts_iosf mei intel_lpss_pci shpchp intel_lpss sch_fq_codel vfio_pci nfsd vfio_virqfd parport_pc ppdev auth_rpcgss nfs_acl lockd grace lp parport sunrpc ip_tables x_tables autofs4 hid_logitech_hidpp hid_logitech_dj hid_generic usbhid kvmgt vfio_mdev mdev vfio_iommu_type1 vfio kvm irqbypass i915 i2c_algo_bit drm_kms_helper syscopyarea sdhci_pci sysfillrect [ 43.178337] sysimgblt cqhci fb_sys_fops sdhci drm i2c_hid wmi hid video pinctrl_sunrisepoint pinctrl_intel [ 43.178380] CPU: 1 PID: 711 Comm: systemd-udevd Tainted: G W 4.16.0 #1 [ 43.178411] Hardware name: LENOVO 80UE/VIUU4, BIOS 2UCN10T 10/14/2016 [ 43.178441] RIP: 0010:__video_register_device+0x1cc/0x1090 [videodev] [ 43.178467] RSP: 0000:ffffa5c5c231b420 EFLAGS: 00010202 [ 43.178490] RAX: ffffffffc0c44cc0 RBX: 0000000000000005 RCX: ffffffffc0c454c0 [ 43.178519] RDX: 0000000000000001 RSI: ffff8eda1d6d9118 RDI: ffffffffc0c44cc0 [ 43.178549] RBP: ffffa5c5c231b478 R08: ffffffffc0c96900 R09: ffff8eda1a51f018 [ 43.178579] R10: 0000000000000600 R11: 00000000000003b6 R12: 0000000000000000 [ 43.178608] R13: 0000000000000005 R14: ffffffffc0c96900 R15: ffff8eda1d6d91c0 [ 43.178636] FS: 00007fd2d8ef2480(0000) GS:ffff8eda33480000(0000) knlGS:0000000000000000 [ 43.178669] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 43.178693] CR2: 0000000000000499 CR3: 0000000456ae2004 CR4: 00000000003606e0 [ 43.178721] Call Trace: [ 43.178736] ? devres_add+0x5f/0x70 [ 43.178755] rmi_f54_probe+0x437/0x470 [rmi_core] [ 43.178779] rmi_function_probe+0x25/0x30 [rmi_core] [ 43.178805] driver_probe_device+0x310/0x480 [ 43.178828] __device_attach_driver+0x86/0x100 [ 43.178851] ? __driver_attach+0xf0/0xf0 [ 43.178884] bus_for_each_drv+0x6b/0xb0 [ 43.178904] __device_attach+0xdd/0x160 [ 43.178925] device_initial_probe+0x13/0x20 [ 43.178948] bus_probe_device+0x95/0xa0 [ 43.178968] device_add+0x44b/0x680 [ 43.178987] rmi_register_function+0x62/0xd0 [rmi_core] [ 43.181747] rmi_create_function+0x112/0x1a0 [rmi_core] [ 43.184677] ? rmi_driver_clear_irq_bits+0xc0/0xc0 [rmi_core] [ 43.187505] rmi_scan_pdt+0xca/0x1a0 [rmi_core] [ 43.190171] rmi_init_functions+0x5b/0x120 [rmi_core] [ 43.192809] rmi_driver_probe+0x152/0x3c0 [rmi_core] [ 43.195403] ? sysfs_create_link+0x25/0x40 [ 43.198253] driver_probe_device+0x310/0x480 [ 43.201083] __device_attach_driver+0x86/0x100 [ 43.203800] ? __driver_attach+0xf0/0xf0 [ 43.206503] bus_for_each_drv+0x6b/0xb0 [ 43.209291] __device_attach+0xdd/0x160 [ 43.212207] device_initial_probe+0x13/0x20 [ 43.215146] bus_probe_device+0x95/0xa0 [ 43.217885] device_add+0x44b/0x680 [ 43.220597] rmi_register_transport_device+0x84/0x100 [rmi_core] [ 43.223321] rmi_input_configured+0xbf/0x1a0 [hid_rmi] [ 43.226051] ? input_allocate_device+0xdf/0xf0 [ 43.228814] hidinput_connect+0x4a9/0x37a0 [hid] [ 43.231701] hid_connect+0x326/0x3d0 [hid] [ 43.234548] hid_hw_start+0x42/0x70 [hid] [ 43.237302] rmi_probe+0x115/0x510 [hid_rmi] [ 43.239862] hid_device_probe+0xd3/0x150 [hid] [ 43.242558] ? sysfs_create_link+0x25/0x40 [ 43.242828] audit: type=1400 audit(1522795151.600:4): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/snap/core/4206/usr/lib/snapd/snap-confine" pid=1151 comm="apparmor_parser" [ 43.244859] driver_probe_device+0x310/0x480 [ 43.244862] __driver_attach+0xbf/0xf0 [ 43.246982] audit: type=1400 audit(1522795151.600:5): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/snap/core/4206/usr/lib/snapd/snap-confine//mount-namespace-capture-helper" pid=1151 comm="apparmor_parser" [ 43.249403] ? driver_probe_device+0x480/0x480 [ 43.249405] bus_for_each_dev+0x74/0xb0 [ 43.253200] audit: type=1400 audit(1522795151.600:6): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/snap/core/4206/usr/lib/snapd/snap-confine//snap_update_ns" pid=1151 comm="apparmor_parser" [ 43.254055] ? kmem_cache_alloc_trace+0x1a6/0x1c0 [ 43.256282] audit: type=1400 audit(1522795151.604:7): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/sbin/dhclient" pid=1152 comm="apparmor_parser" [ 43.258436] driver_attach+0x1e/0x20 [ 43.260875] audit: type=1400 audit(1522795151.604:8): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=1152 comm="apparmor_parser" [ 43.263118] bus_add_driver+0x167/0x260 [ 43.267676] audit: type=1400 audit(1522795151.604:9): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-helper" pid=1152 comm="apparmor_parser" [ 43.268807] ? 0xffffffffc0cbc000 [ 43.268812] driver_register+0x60/0xe0 [ 43.271184] audit: type=1400 audit(1522795151.604:10): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/lib/connman/scripts/dhclient-script" pid=1152 comm="apparmor_parser" [ 43.274081] ? 0xffffffffc0cbc000 [ 43.274086] __hid_register_driver+0x63/0x70 [hid] [ 43.288367] rmi_driver_init+0x23/0x1000 [hid_rmi] [ 43.291501] do_one_initcall+0x52/0x191 [ 43.292348] audit: type=1400 audit(1522795151.652:11): apparmor="STATUS" operation="profile_load" profile="unconfined" name="/usr/bin/man" pid=1242 comm="apparmor_parser" [ 43.294212] ? _cond_resched+0x19/0x40 [ 43.300028] ? kmem_cache_alloc_trace+0xa2/0x1c0 [ 43.303475] ? do_init_module+0x27/0x209 [ 43.306842] do_init_module+0x5f/0x209 [ 43.310269] load_module+0x1987/0x1f10 [ 43.313704] ? ima_post_read_file+0x96/0xa0 [ 43.317174] SYSC_finit_module+0xfc/0x120 [ 43.320754] ? SYSC_finit_module+0xfc/0x120 [ 43.324065] SyS_finit_module+0xe/0x10 [ 43.327387] do_syscall_64+0x73/0x130 [ 43.330909] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 43.334305] RIP: 0033:0x7fd2d880b839 [ 43.337810] RSP: 002b:00007ffe0a6b2368 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 43.341259] RAX: ffffffffffffffda RBX: 000055cdd86542e0 RCX: 00007fd2d880b839 [ 43.344613] RDX: 0000000000000000 RSI: 00007fd2d84ea0e5 RDI: 0000000000000016 [ 43.347962] RBP: 00007fd2d84ea0e5 R08: 0000000000000000 R09: 00007ffe0a6b2480 [ 43.351456] R10: 0000000000000016 R11: 0000000000000246 R12: 0000000000000000 [ 43.354845] R13: 000055cdd8688930 R14: 0000000000020000 R15: 000055cdd86542e0 [ 43.358224] Code: c7 05 ad 12 02 00 00 00 00 00 48 8d 88 00 08 00 00 eb 09 48 83 c0 08 48 39 c1 74 31 48 8b 10 48 85 d2 74 ef 49 8b b7 98 04 00 00 <48> 39 b2 98 04 00 00 75 df 48 63 92 f8 04 00 00 f0 48 0f ab 15 [ 43.361764] RIP: __video_register_device+0x1cc/0x1090 [videodev] RSP: ffffa5c5c231b420 [ 43.365281] CR2: 0000000000000499
This patch fixes the array size and changes the WARN_ON() to return an error, instead of letting the Kernel to proceed with registering.
Cc: stable@vger.kernel.org Reported-by: Peter Geis pgwipeout@gmail.com Reported-by: Jaak Ristioja jaak@ristioja.ee Reported-by: Michał Siemek mihau69@gmail.com Signed-off-by: Mauro Carvalho Chehab mchehab@s-opensource.com --- drivers/media/v4l2-core/v4l2-dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c index 0301fe426a43..cc95d6023d57 100644 --- a/drivers/media/v4l2-core/v4l2-dev.c +++ b/drivers/media/v4l2-core/v4l2-dev.c @@ -93,7 +93,7 @@ ATTRIBUTE_GROUPS(video_device); */ static struct video_device *video_device[VIDEO_NUM_DEVICES]; static DEFINE_MUTEX(videodev_lock); -static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES); +static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX + 1], VIDEO_NUM_DEVICES);
/* Device node utility functions */
@@ -942,7 +942,11 @@ int __video_register_device(struct video_device *vdev, devnode_set(vdev);
/* Should not happen since we thought this minor was free */ - WARN_ON(video_device[vdev->minor] != NULL); + if (WARN_ON(video_device[vdev->minor])) { + mutex_unlock(&videodev_lock); + printk(KERN_ERR "video_device not empty!\n"); + return -ENFILE; + } vdev->index = get_index(vdev); video_device[vdev->minor] = vdev; mutex_unlock(&videodev_lock);