| Message ID | 20210914104253.61365-2-sven@svenpeter.dev (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] usb: typec: tipd: Don't read/write more bytes than required | expand |
On Tue, Sep 14, 2021 at 12:42:53PM +0200, Sven Peter wrote: > tps6598x_block_read already checks for the maximum length of the read > but tps6598x_block_write does not. Add the symmetric check there as > well. > > Signed-off-by: Sven Peter <sven@svenpeter.dev> > --- > drivers/usb/typec/tipd/core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c > index c18ec3785592..70e2d0d410c9 100644 > --- a/drivers/usb/typec/tipd/core.c > +++ b/drivers/usb/typec/tipd/core.c > @@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg, > { > u8 data[TPS_MAX_LEN + 1]; > > + if (WARN_ON(len + 1 > sizeof(data))) > + return -EINVAL; No need to crash anything. If this is a valid thing for us to check, let's check it and handle the error, but we should not reboot systems that are running with panic-on-warn enabled, right? thanks, greg k-h
On Tue, Sep 14, 2021, at 13:00, Greg Kroah-Hartman wrote: > On Tue, Sep 14, 2021 at 12:42:53PM +0200, Sven Peter wrote: > > tps6598x_block_read already checks for the maximum length of the read > > but tps6598x_block_write does not. Add the symmetric check there as > > well. > > > > Signed-off-by: Sven Peter <sven@svenpeter.dev> > > --- > > drivers/usb/typec/tipd/core.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c > > index c18ec3785592..70e2d0d410c9 100644 > > --- a/drivers/usb/typec/tipd/core.c > > +++ b/drivers/usb/typec/tipd/core.c > > @@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg, > > { > > u8 data[TPS_MAX_LEN + 1]; > > > > + if (WARN_ON(len + 1 > sizeof(data))) > > + return -EINVAL; > > No need to crash anything. If this is a valid thing for us to check, > let's check it and handle the error, but we should not reboot systems > that are running with panic-on-warn enabled, right? Sure, that makes sense. I guess the same point applies to the WARN_ON in the same check in tps6598x_block_read. I can add a patch to remove that one to v2 as well. thanks, Sven
On Tue, Sep 14, 2021 at 01:18:16PM +0200, Sven Peter wrote: > > > On Tue, Sep 14, 2021, at 13:00, Greg Kroah-Hartman wrote: > > On Tue, Sep 14, 2021 at 12:42:53PM +0200, Sven Peter wrote: > > > tps6598x_block_read already checks for the maximum length of the read > > > but tps6598x_block_write does not. Add the symmetric check there as > > > well. > > > > > > Signed-off-by: Sven Peter <sven@svenpeter.dev> > > > --- > > > drivers/usb/typec/tipd/core.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c > > > index c18ec3785592..70e2d0d410c9 100644 > > > --- a/drivers/usb/typec/tipd/core.c > > > +++ b/drivers/usb/typec/tipd/core.c > > > @@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg, > > > { > > > u8 data[TPS_MAX_LEN + 1]; > > > > > > + if (WARN_ON(len + 1 > sizeof(data))) > > > + return -EINVAL; > > > > No need to crash anything. If this is a valid thing for us to check, > > let's check it and handle the error, but we should not reboot systems > > that are running with panic-on-warn enabled, right? > > Sure, that makes sense. I guess the same point applies to the WARN_ON in > the same check in tps6598x_block_read. I can add a patch to remove that one > to v2 as well. That would be great, thanks. greg k-h
diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c index c18ec3785592..70e2d0d410c9 100644 --- a/drivers/usb/typec/tipd/core.c +++ b/drivers/usb/typec/tipd/core.c @@ -139,6 +139,9 @@ static int tps6598x_block_write(struct tps6598x *tps, u8 reg, { u8 data[TPS_MAX_LEN + 1]; + if (WARN_ON(len + 1 > sizeof(data))) + return -EINVAL; + if (!tps->i2c_protocol) return regmap_raw_write(tps->regmap, reg, val, len);
tps6598x_block_read already checks for the maximum length of the read but tps6598x_block_write does not. Add the symmetric check there as well. Signed-off-by: Sven Peter <sven@svenpeter.dev> --- drivers/usb/typec/tipd/core.c | 3 +++ 1 file changed, 3 insertions(+)