[PATCH] clk: hisilicon: hi3559a: Fix an erroneous devm_kfree()

[PATCH] clk: hisilicon: hi3559a: Fix an erroneous devm_kfree()

[Christophe JAILLET]

'p_clk' is an array allocated just before the for loop for all clk that
need to be registered.
It is incremented at each loop iteration.

If a clk_register() call fails, 'p_clk' may point to something different
from what should be freed.

The best we can do, is to avoid this wrong release of memory.

Fixes: 6c81966107dc ("clk: hisilicon: Add clock driver for hi3559A SoC")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
devm_kfree() is clearly wrong (IMHO :)), but just removing it is maybe not
the best solution.

Should hisi_clk_register_pll() return an error?
Should some data->clk_data.clks[clks[i].id] be set to NULL?
(hisi_clk_alloc() doesn't zero the allocated memory)
Should hisi_clk_alloc() use kzalloc() when allocating clk_table?
---
 drivers/clk/hisilicon/clk-hi3559a.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/clk/hisilicon/clk-hi3559a.c b/drivers/clk/hisilicon/clk-hi3559a.c
index ff4ca0edce06..4623befafaec 100644
--- a/drivers/clk/hisilicon/clk-hi3559a.c
+++ b/drivers/clk/hisilicon/clk-hi3559a.c
@@ -491,7 +491,6 @@ static void hisi_clk_register_pll(struct hi3559av100_pll_clock *clks,
 
 		clk = clk_register(NULL, &p_clk->hw);
 		if (IS_ERR(clk)) {
-			devm_kfree(dev, p_clk);
 			dev_err(dev, "%s: failed to register clock %s\n",
 			       __func__, clks[i].name);
 			continue;
-- 
2.43.0

Re: [PATCH] clk: hisilicon: hi3559a: Fix an erroneous devm_kfree()

[Stephen Boyd]

Quoting Christophe JAILLET (2024-01-21 07:16:24)
> 'p_clk' is an array allocated just before the for loop for all clk that
> need to be registered.
> It is incremented at each loop iteration.
> 
> If a clk_register() call fails, 'p_clk' may point to something different
> from what should be freed.
> 
> The best we can do, is to avoid this wrong release of memory.
> 
> Fixes: 6c81966107dc ("clk: hisilicon: Add clock driver for hi3559A SoC")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---

Applied to clk-next

About doing the right thing, it seems OK to remove the free for now
because the code continues on anyway.