Messages in this thread | | | Date | Fri, 8 May 2015 10:19:55 -0700 | From | Dmitry Torokhov <> | Subject | Re: [PATCH] PM / clock_ops: Fix clock error check in __pm_clk_add() |
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On Fri, May 08, 2015 at 10:47:43AM +0200, Geert Uytterhoeven wrote: > In the final iteration of commit 245bd6f6af8a62a2 ("PM / clock_ops: Add > pm_clk_add_clk()"), a refcount increment was added by Grygorii Strashko. > However, the accompanying IS_ERR() check operates on the wrong clock > pointer, which is always zero at this point, i.e. not an error. > This may lead to a NULL pointer dereference later, when __clk_get() > tries to dereference an error pointer. > > Check the passed clock pointer instead to fix this.
Frankly I would remove the check altogether. Why do we only check for IS_ERR and not NULL or otherwise validate the pointer? The clk is passed in and we do not call any API that would return ERR_PTR-encoded value to us so we shoud lnot even try to handle IS_ERR here.
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > Fixes: 245bd6f6af8a62a2 ("PM / clock_ops: Add pm_clk_add_clk()") > --- > Note that there are no users of pm_clk_add_clk() in next-20150508, so > for now no in-tree code is affected. > --- > drivers/base/power/clock_ops.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c > index 7fdd0172605afe1b..c7b0fcebf168cabe 100644 > --- a/drivers/base/power/clock_ops.c > +++ b/drivers/base/power/clock_ops.c > @@ -93,7 +93,7 @@ static int __pm_clk_add(struct device *dev, const char *con_id, > return -ENOMEM; > } > } else { > - if (IS_ERR(ce->clk) || !__clk_get(clk)) { > + if (IS_ERR(clk) || !__clk_get(clk)) { > kfree(ce); > return -ENOENT; > } > -- > 1.9.1 >
Thanks.
-- Dmitry
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