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drm/edid: Fix crash with zero/invalid EDID

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In the commit bac9c29482 ("drm/edid: Break out reading block 0 of
the EDID") I broke out reading the base block of the EDID to its own
function. Unfortunately, when I did that I messed up the handling when
drm_edid_is_zero() indicated that we had an EDID that was all 0x00 or
when we went through 4 loops and didn't get a valid EDID. Specifically
I needed to pass the broken EDID to connector_bad_edid() but now I was
passing an error-pointer.

Let's re-jigger things so we can pass the bad EDID in properly.

Fixes: bac9c29482 ("drm/edid: Break out reading block 0 of the EDID")
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patchwork.freedesktop.org/patch/msgid/20211004092100.1.Ic90a5ebd44c75db963112be167a03cc96f9fb249@changeid
This commit is contained in:
Douglas Anderson 2021-10-04 09:21:27 -07:00
parent 61bae13203
commit e7bd95a7ed
1 changed files with 11 additions and 16 deletions
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27
drivers/gpu/drm/drm_edid.c
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@ -1911,13 +1911,15 @@ int drm_add_override_edid_modes(struct drm_connector *connector)
}
EXPORT_SYMBOL(drm_add_override_edid_modes);
static struct edid *drm_do_get_edid_base_block(
static struct edid *drm_do_get_edid_base_block(struct drm_connector *connector,
int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
size_t len),
void *data, bool *edid_corrupt, int *null_edid_counter)
void *data)
{
int i;
int *null_edid_counter = connector ? &connector->null_edid_counter : NULL;
bool *edid_corrupt = connector ? &connector->edid_corrupt : NULL;
void *edid;
int i;
edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
if (edid == NULL)
@ -1941,9 +1943,8 @@ static struct edid *drm_do_get_edid_base_block(
return edid;
carp:
kfree(edid);
return ERR_PTR(-EINVAL);
if (connector)
connector_bad_edid(connector, edid, 1);
out:
kfree(edid);
return NULL;
@ -1982,14 +1983,9 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
if (override)
return override;
edid = (u8 *)drm_do_get_edid_base_block(get_edid_block, data,
&connector->edid_corrupt,
&connector->null_edid_counter);
if (IS_ERR_OR_NULL(edid)) {
if (IS_ERR(edid))
connector_bad_edid(connector, edid, 1);
edid = (u8 *)drm_do_get_edid_base_block(connector, get_edid_block, data);
if (!edid)
return NULL;
}
/* if there's no extensions or no connector, we're done */
valid_extensions = edid[0x7e];
@ -2142,14 +2138,13 @@ u32 drm_edid_get_panel_id(struct i2c_adapter *adapter)
struct edid *edid;
u32 panel_id;
edid = drm_do_get_edid_base_block(drm_do_probe_ddc_edid, adapter,
NULL, NULL);
edid = drm_do_get_edid_base_block(NULL, drm_do_probe_ddc_edid, adapter);
/*
* There are no manufacturer IDs of 0, so if there is a problem reading
* the EDID then we'll just return 0.
*/
if (IS_ERR_OR_NULL(edid))
if (!edid)
return 0;
panel_id = edid_extract_panel_id(edid);