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| author | Xiaomeng Tong <xiam0nd.tong@gmail.com> | 2022-03-27 14:15:16 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-14 18:11:49 +0200 |
| commit | a62591e36100fab47dac22c38a10663c4ae0453d (patch) | |
| tree | 0ef628a9121d38fe4491c631132b078366ee985c | |
| parent | 77ec584d3de04592176c2a0139cf103d92d263ec (diff) | |
| download | linux-stable-a62591e36100fab47dac22c38a10663c4ae0453d.tar.gz linux-stable-a62591e36100fab47dac22c38a10663c4ae0453d.tar.bz2 linux-stable-a62591e36100fab47dac22c38a10663c4ae0453d.zip | |
tilcdc: tilcdc_external: fix an incorrect NULL check on list iterator
commit 8b917cbe38e9b0d002492477a9fc2bfee2412ce4 upstream.
The bug is here:
if (!encoder) {
The list iterator value 'encoder' will *always* be set and non-NULL
by list_for_each_entry(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
is found.
To fix the bug, use a new variable 'iter' as the list iterator,
while use the original variable 'encoder' as a dedicated pointer
to point to the found element.
Cc: stable@vger.kernel.org
Fixes: ec9eab097a500 ("drm/tilcdc: Add drm bridge support for attaching drm bridge drivers")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
Tested-by: Jyri Sarha <jyri.sarha@iki.fi>
Signed-off-by: Jyri Sarha <jyri.sarha@iki.fi>
Link: https://patchwork.freedesktop.org/patch/msgid/20220327061516.5076-1-xiam0nd.tong@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/tilcdc/tilcdc_external.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_external.c b/drivers/gpu/drm/tilcdc/tilcdc_external.c index 43d756b7810e..67e23317c7de 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_external.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_external.c @@ -58,11 +58,13 @@ struct drm_connector *tilcdc_encoder_find_connector(struct drm_device *ddev, int tilcdc_add_component_encoder(struct drm_device *ddev) { struct tilcdc_drm_private *priv = ddev->dev_private; - struct drm_encoder *encoder; + struct drm_encoder *encoder = NULL, *iter; - list_for_each_entry(encoder, &ddev->mode_config.encoder_list, head) - if (encoder->possible_crtcs & (1 << priv->crtc->index)) + list_for_each_entry(iter, &ddev->mode_config.encoder_list, head) + if (iter->possible_crtcs & (1 << priv->crtc->index)) { + encoder = iter; break; + } if (!encoder) { dev_err(ddev->dev, "%s: No suitable encoder found\n", __func__); |