From 50ce6826a48f119baf2794fa384a64efe9bd84a5 Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Wed, 7 Apr 2021 02:06:06 +0300 Subject: [PATCH] clk: fixed: fix double free in resource managed fixed-factor clock devm_clk_hw_register_fixed_factor_release(), the release function for the devm_clk_hw_register_fixed_factor(), calls clk_hw_unregister_fixed_factor(), which will kfree() the clock. However after that the devres functions will also kfree the allocated data, resulting in double free/memory corruption. Just call clk_hw_unregister() instead, leaving kfree() to devres code. Reported-by: Rob Clark Cc: Daniel Palmer Signed-off-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20210406230606.3007138-1-dmitry.baryshkov@linaro.org Fixes: 0b9266d295ce ("clk: fixed: add devm helper for clk_hw_register_fixed_factor()") [sboyd@kernel.org: Remove ugly cast] Signed-off-by: Stephen Boyd --- drivers/clk/clk-fixed-factor.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c index 4f7bf3929d6d..4e4b6d367612 100644 --- a/drivers/clk/clk-fixed-factor.c +++ b/drivers/clk/clk-fixed-factor.c @@ -66,7 +66,14 @@ EXPORT_SYMBOL_GPL(clk_fixed_factor_ops); static void devm_clk_hw_register_fixed_factor_release(struct device *dev, void *res) { - clk_hw_unregister_fixed_factor(&((struct clk_fixed_factor *)res)->hw); + struct clk_fixed_factor *fix = res; + + /* + * We can not use clk_hw_unregister_fixed_factor, since it will kfree() + * the hw, resulting in double free. Just unregister the hw and let + * devres code kfree() it. + */ + clk_hw_unregister(&fix->hw); } static struct clk_hw * -- 2.11.0