[PATCH v2] clk: renesas: cpg-mssr: Fix use after free if cpg_mssr_common_init() failed

From: Alexey Khoroshilov
Date: Fri Dec 23 2022 - 09:40:38 EST


If cpg_mssr_common_init() fails after assigning priv to global variable
cpg_mssr_priv, it deallocates priv, but cpg_mssr_priv keeps dangling
pointer that potentially can be used later.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 1f7db7bbf031 ("clk: renesas: cpg-mssr: Add early clock support")
Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
v2: Move cpg_mssr_priv assignment just before return 0; instead of
clearing it as Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> suggested.
drivers/clk/renesas/renesas-cpg-mssr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/renesas/renesas-cpg-mssr.c b/drivers/clk/renesas/renesas-cpg-mssr.c
index 1a0cdf001b2f..5dce9779324d 100644
--- a/drivers/clk/renesas/renesas-cpg-mssr.c
+++ b/drivers/clk/renesas/renesas-cpg-mssr.c
@@ -989,7 +989,6 @@ static int __init cpg_mssr_common_init(struct device *dev,
goto out_err;
}

- cpg_mssr_priv = priv;
priv->num_core_clks = info->num_total_core_clks;
priv->num_mod_clks = info->num_hw_mod_clks;
priv->last_dt_core_clk = info->last_dt_core_clk;
@@ -1019,6 +1018,8 @@ static int __init cpg_mssr_common_init(struct device *dev,
if (error)
goto out_err;

+ cpg_mssr_priv = priv;
+
return 0;

out_err:
--
2.7.4