linux-stable/drivers/gpu/drm/bridge
Geert Uytterhoeven 5ad773f9a9 drm/bridge: dumb-vga-dac: Fix dereferencing -ENODEV DDC channel
If the VGA connector has no DDC channel, an error pointer will be
dereferenced, e.g. on Salvator-XS:

    Unable to handle kernel NULL pointer dereference at virtual address 000000000000017d
    ...
    Call trace:
     sysfs_do_create_link_sd.isra.0+0x40/0x108
     sysfs_create_link+0x20/0x40
     drm_sysfs_connector_add+0xa8/0xc8
     drm_connector_register.part.3+0x54/0xb0
     drm_connector_register_all+0xb0/0xd0
     drm_modeset_register_all+0x54/0x88
     drm_dev_register+0x18c/0x1d8
     rcar_du_probe+0xe4/0x150
     ...

This happens because vga->ddc either contains a valid DDC channel
pointer, or -ENODEV, and drm_connector_init_with_ddc() expects a valid
DDC channel pointer, or NULL.

Fix this by resetting vga->ddc to NULL in case of -ENODEV, and replacing
the existing error checks by non-NULL checks.
This is similar to what the HDMI connector driver does.

Fixes: a4f9087e85 ("drm/bridge: dumb-vga-dac: Provide ddc symlink in connector sysfs directory")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190813093046.4976-1-geert+renesas@glider.be
2019-08-14 16:44:04 +02:00
..
adv7511 drm/bridge: adv7511: Attach to DSI host at probe time 2019-07-01 12:29:15 +02:00
analogix drm/panel: drop return code from drm_panel_detach() 2019-08-10 15:41:48 +02:00
synopsys drm/bridge: dw-hdmi-i2s: add .get_eld support 2019-08-14 15:03:36 +02:00
analogix-anx78xx.c Linux 5.2-rc5 2019-06-19 12:07:29 +02:00
analogix-anx78xx.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284 2019-06-05 17:36:37 +02:00
cdns-dsi.c drm/bridge: cdns: Convert to phy framework 2019-02-07 09:48:40 +01:00
dumb-vga-dac.c drm/bridge: dumb-vga-dac: Fix dereferencing -ENODEV DDC channel 2019-08-14 16:44:04 +02:00
Kconfig drm/bridge: Improve the help text for DRM_ANALOGIX_ANX78XX 2019-07-22 16:08:06 -04:00
lvds-encoder.c Linux 5.2-rc5 2019-06-19 12:07:29 +02:00
Makefile drm/bridge: tc358764: Add DSI to LVDS bridge driver 2018-07-27 09:09:57 +02:00
megachips-stdpxxxx-ge-b850v3-fw.c drm/bridge/megachips: Drop GPIO header 2019-08-05 18:42:15 +02:00
nxp-ptn3460.c drm/bridge/nxp-ptn3460: Drop legacy GPIO headers 2019-08-05 18:48:07 +02:00
panel.c Linux 5.2-rc5 2019-06-19 12:07:29 +02:00
parade-ps8622.c drm/bridge/parade: Drop legacy GPIO header 2019-08-05 18:50:50 +02:00
sii902x.c drm/bridge: sii902x: add audio graph card support 2019-07-25 14:20:02 +02:00
sii9234.c gpu: drm: bridge: sii9234: simplify getting the adapter of a client 2019-06-12 16:01:30 +02:00
sil-sii8620.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sil-sii8620.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
tc358764.c drm/bridge: drop drmP.h usage 2019-05-26 10:55:04 +02:00
tc358767.c drm/bridge: tc358767: fix opencoded use of drm_panel_* 2019-08-10 15:41:47 +02:00
thc63lvd1024.c R-Car DU changes for v5.3: 2019-06-11 10:08:49 +02:00
ti-sn65dsi86.c drm/bridge: ti-sn65dsi86: use dev name for debugfs 2019-07-16 09:53:03 +02:00
ti-tfp410.c drm/bridge: ti-tfp410: Provide ddc symlink in connector sysfs directory 2019-07-31 16:34:55 +02:00