| From | Geert Uytterhoeven <> | Date | Mon, 6 May 2019 10:21:28 +0200 | Subject | Re: [PATCH 5.0 100/101] leds: pca9532: fix a potential NULL pointer dereference |
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Hi Greg,
On Thu, May 2, 2019 at 5:34 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > [ Upstream commit 0aab8e4df4702b31314a27ec4b0631dfad0fae0a ] > > In case of_match_device cannot find a match, return -EINVAL to avoid > NULL pointer dereference. > > Fixes: fa4191a609f2 ("leds: pca9532: Add device tree support") > Signed-off-by: Kangjie Lu <kjlu@umn.edu> > Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com> > Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
> --- a/drivers/leds/leds-pca9532.c > +++ b/drivers/leds/leds-pca9532.c > @@ -513,6 +513,7 @@ static int pca9532_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > int devid; > + const struct of_device_id *of_id; > struct pca9532_data *data = i2c_get_clientdata(client); > struct pca9532_platform_data *pca9532_pdata = > dev_get_platdata(&client->dev); > @@ -528,8 +529,11 @@ static int pca9532_probe(struct i2c_client *client, > dev_err(&client->dev, "no platform data\n"); > return -EINVAL; > } > - devid = (int)(uintptr_t)of_match_device( > - of_pca9532_leds_match, &client->dev)->data; > + of_id = of_match_device(of_pca9532_leds_match, > + &client->dev); > + if (unlikely(!of_id))
This condition (1) can never be true, as of_pca9532_leds_match[] populates the .data field of all entries, and (2) is already checked for in pca9532_of_populate_pdata(), so pca9532_probe() would already have aborted with -ENODEV before.
https://lore.kernel.org/lkml/CAMuHMdXELu2tcSB5C1yKUGft6sDGPAy997ApPzy17n0MssfyWA@mail.gmail.com/
So please stop backporting this to even more stable trees. Thanks!
> + return -EINVAL; > + devid = (int)(uintptr_t) of_id->data; > } else { > devid = id->driver_data; > }
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
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
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