Re: [PATCH] pinctrl: sophgo: fix double free in cv1800_pctrl_dt_node_to_map()

[Dan Carpenter]

On Thu, Oct 10, 2024 at 07:17:19PM +0200, Christophe JAILLET wrote:
> Le 10/10/2024 à 13:18, Harshit Mogalapalli a écrit :
> > 'map' is allocated using devm_* which takes care of freeing the allocated
> > data, but in error paths there is a call to pinctrl_utils_free_map()
> > which also does kfree(map) which leads to a double free.
> > 
> > Use kcalloc() instead of devm_kcalloc() as freeing is manually handled.
> > 
> > Fixes: a29d8e93e710 ("pinctrl: sophgo: add support for CV1800B SoC")
> > Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
> > ---
> > This is based on static analysis with smatch, only compile tested.
> > ---
> >   drivers/pinctrl/sophgo/pinctrl-cv18xx.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/pinctrl/sophgo/pinctrl-cv18xx.c b/drivers/pinctrl/sophgo/pinctrl-cv18xx.c
> > index d18fc5aa84f7..57f2674e75d6 100644
> > --- a/drivers/pinctrl/sophgo/pinctrl-cv18xx.c
> > +++ b/drivers/pinctrl/sophgo/pinctrl-cv18xx.c
> > @@ -221,7 +221,7 @@ static int cv1800_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
> >   	if (!grpnames)
> >   		return -ENOMEM;
> > -	map = devm_kcalloc(dev, ngroups * 2, sizeof(*map), GFP_KERNEL);
> > +	map = kcalloc(ngroups * 2, sizeof(*map), GFP_KERNEL);
> >   	if (!map)
> >   		return -ENOMEM;
> 
> Hi,
> 
> drivers/pinctrl/nuvoton/pinctrl-ma35.c seems to have the same issue.
> 

Yep.  That one is too complicated for Smatch to find.  In this case, the kfree()
happened in the cleanup so it was in the same function.

regards,
dan carpenter