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 <[email protected]>
---
drivers/clk/renesas/renesas-cpg-mssr.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/clk/renesas/renesas-cpg-mssr.c b/drivers/clk/renesas/renesas-cpg-mssr.c
index 1a0cdf001b2f..27da127ca4a8 100644
--- a/drivers/clk/renesas/renesas-cpg-mssr.c
+++ b/drivers/clk/renesas/renesas-cpg-mssr.c
@@ -1025,6 +1025,7 @@ static int __init cpg_mssr_common_init(struct device *dev,
if (priv->base)
iounmap(priv->base);
kfree(priv);
+ cpg_mssr_priv = NULL;
return error;
}
--
2.7.4
Hi Alexey,
On Thu, Dec 22, 2022 at 11:23 PM Alexey Khoroshilov
<[email protected]> wrote:
> 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 <[email protected]>
Thanks for your patch!
> --- a/drivers/clk/renesas/renesas-cpg-mssr.c
> +++ b/drivers/clk/renesas/renesas-cpg-mssr.c
> @@ -1025,6 +1025,7 @@ static int __init cpg_mssr_common_init(struct device *dev,
> if (priv->base)
> iounmap(priv->base);
> kfree(priv);
> + cpg_mssr_priv = NULL;
While this is correct, I think it would be better to just postpone
the initial assignment to cpg_mssr_priv until everything in
cpg_mssr_common_init() has succeeded, i.e. just below the
"return 0;" above.
>
> return error;
> }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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 <[email protected]>
---
v2: Move cpg_mssr_priv assignment just before return 0; instead of
clearing it as Geert Uytterhoeven <[email protected]> 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
On Fri, Dec 23, 2022 at 3:40 PM Alexey Khoroshilov
<[email protected]> wrote:
> 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 <[email protected]>
> ---
> v2: Move cpg_mssr_priv assignment just before return 0; instead of
> clearing it as Geert Uytterhoeven <[email protected]> suggested.
Reviewed-by: Geert Uytterhoeven <[email protected]>
i.e. will queue in renesas-clk-for-v6.3.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds