Hi Am 03.02.22 um 16:23 schrieb trix@xxxxxxxxxx:
From: Tom Rix <trix@xxxxxxxxxx> clang static analysis reports this problem ast_mode.c:1235:3: warning: Use of memory after it is freed drm_connector_update_edid_property(&ast_connector->base, edid); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The second condition on if (!flags && ast_connector->i2c) Means that the edid is not always set. If the previous block fails the freed edid value will be used. So set edid to NULL after freeing.
Thanks for your patch. We have meanwhile merges a change that replaces the code entirely.
Best regards Thomas
Fixes: 55dc449a7c60 ("drm/ast: Handle failed I2C initialization gracefully") Signed-off-by: Tom Rix <trix@xxxxxxxxxx> --- drivers/gpu/drm/ast/ast_mode.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index ab52efb15670e..9131dc8a1a2fc 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1224,10 +1224,12 @@ static int ast_get_modes(struct drm_connector *connector) return -ENOMEM;flags = ast_dp501_read_edid(connector->dev, (u8 *)edid);- if (flags) + if (flags) { ast->dp501_maxclk = ast_get_dp501_max_clk(connector->dev); - else + } else { kfree(edid); + edid = NULL; + } } if (!flags && ast_connector->i2c) edid = drm_get_edid(connector, &ast_connector->i2c->adapter);
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev
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