Messages in this thread Patch in this message | | | From | trix@redhat ... | Subject | [PATCH] drm/ast: fix using freed memory | Date | Thu, 3 Feb 2022 07:23:05 -0800 |
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From: Tom Rix <trix@redhat.com>
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.
Fixes: 55dc449a7c60 ("drm/ast: Handle failed I2C initialization gracefully") Signed-off-by: Tom Rix <trix@redhat.com> --- 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); -- 2.26.3
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