[PATCH 6.4 266/800] clk: imx: scu: use _safe list iterator to avoid a use after free

Greg Kroah-Hartman
2023-07-16T20:05:16Z

From: Dan Carpenter <dan.carpenter@linaro.org>

[ Upstream commit 632c60ecd25dbacee54d5581fe3aeb834b57010a ]

This loop is freeing "clk" so it needs to use list_for_each_entry_safe().
Otherwise it dereferences a freed variable to get the next item on the
loop.

Fixes: 77d8f3068c63 ("clk: imx: scu: add two cells binding support")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/0793fbd1-d2b5-4ec2-9403-3c39343a3e2d@kili.mountain
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/imx/clk-scu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c
index 1e6870f3671f6..db307890e4c16 100644
--- a/drivers/clk/imx/clk-scu.c
+++ b/drivers/clk/imx/clk-scu.c
@@ -707,11 +707,11 @@ struct clk_hw *imx_clk_scu_alloc_dev(const char *name,

void imx_clk_scu_unregister(void)
{
- struct imx_scu_clk_node *clk;
+ struct imx_scu_clk_node *clk, *n;
int i;

for (i = 0; i < IMX_SC_R_LAST; i++) {
- list_for_each_entry(clk, &imx_scu_clks[i], node) {
+ list_for_each_entry_safe(clk, n, &imx_scu_clks[i], node) {
clk_hw_unregister(clk->hw);
kfree(clk);
}
--
2.39.2