| Message ID | 1463967746-15336-1-git-send-email-christopherarges@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Chris, On Sun, May 22, 2016 at 6:42 PM, Chris J Arges <christopherarges@gmail.com> wrote: > I've noticed crashes when using my x60t using a coreboot bios. When using > the pen I can produce a crash simply by tapping a few times. This > generates an event which has an idx of 0xc. This in turn crashes the > machine because the array access is greater than W8001_MAX_LENGTH. This > patch checks for bogus values and filters them in order to prevent crashes. Thank you for submitting a patch in addition to reporting the issue. > Signed-off-by: Chris J Arges <christopherarges@gmail.com> > --- > drivers/input/touchscreen/wacom_w8001.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c > index bab3c6a..c858200 100644 > --- a/drivers/input/touchscreen/wacom_w8001.c > +++ b/drivers/input/touchscreen/wacom_w8001.c > @@ -283,6 +283,15 @@ static irqreturn_t w8001_interrupt(struct serio *serio, > unsigned char tmp; > > w8001->data[w8001->idx] = data; > + > + /* ignore bogus idx values */ > + if (w8001->idx >= W8001_MAX_LENGTH) { > + pr_info("w8001: ignored interrupt: data 0x%02x idx %d\n", data, > + w8001->idx); > + w8001->idx = 0; > + return IRQ_HANDLED; > + } > + I don't have an x60t system to test with. I wonder if your system supports two finger touch or not. We at least have a bug in the code since W8001_MAX_LENGTH should be 13 instead of 11. How come no one had encountered that issue before? I'm going to email a patch to the list. Please test it and let us know your result. Maybe we still need your patch if your device doesn't support two finger touch or the idx=0xc can't be fixed by W8001_MAX_LENGTH=13. Thanks, Ping > switch (w8001->idx++) { > case 0: > if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) { > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-input" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, May 22, 2016 at 10:21:45PM -0700, Ping Cheng wrote: > Hi Chris, > > On Sun, May 22, 2016 at 6:42 PM, Chris J Arges > <christopherarges@gmail.com> wrote: > > I've noticed crashes when using my x60t using a coreboot bios. When using > > the pen I can produce a crash simply by tapping a few times. This > > generates an event which has an idx of 0xc. This in turn crashes the > > machine because the array access is greater than W8001_MAX_LENGTH. This > > patch checks for bogus values and filters them in order to prevent crashes. > > Thank you for submitting a patch in addition to reporting the issue. > > > Signed-off-by: Chris J Arges <christopherarges@gmail.com> > > --- > > drivers/input/touchscreen/wacom_w8001.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c > > index bab3c6a..c858200 100644 > > --- a/drivers/input/touchscreen/wacom_w8001.c > > +++ b/drivers/input/touchscreen/wacom_w8001.c > > @@ -283,6 +283,15 @@ static irqreturn_t w8001_interrupt(struct serio *serio, > > unsigned char tmp; > > > > w8001->data[w8001->idx] = data; > > + > > + /* ignore bogus idx values */ > > + if (w8001->idx >= W8001_MAX_LENGTH) { > > + pr_info("w8001: ignored interrupt: data 0x%02x idx %d\n", data, > > + w8001->idx); > > + w8001->idx = 0; > > + return IRQ_HANDLED; > > + } > > + > > I don't have an x60t system to test with. I wonder if your system > supports two finger touch or not. We at least have a bug in the code > since W8001_MAX_LENGTH should be 13 instead of 11. How come no one had > encountered that issue before? > > I'm going to email a patch to the list. Please test it and let us know > your result. Maybe we still need your patch if your device doesn't > support two finger touch or the idx=0xc can't be fixed by > W8001_MAX_LENGTH=13. Just so we are clear this version of the patch is buggy as we check the index only after [potentially] writing past the array bounds of w8001->data[]. Thanks.
On Mon, May 23, 2016 at 9:52 AM, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > On Sun, May 22, 2016 at 10:21:45PM -0700, Ping Cheng wrote: >> Hi Chris, >> >> On Sun, May 22, 2016 at 6:42 PM, Chris J Arges >> <christopherarges@gmail.com> wrote: >> > I've noticed crashes when using my x60t using a coreboot bios. When using >> > the pen I can produce a crash simply by tapping a few times. This >> > generates an event which has an idx of 0xc. This in turn crashes the >> > machine because the array access is greater than W8001_MAX_LENGTH. This >> > patch checks for bogus values and filters them in order to prevent crashes. >> >> Thank you for submitting a patch in addition to reporting the issue. >> >> > Signed-off-by: Chris J Arges <christopherarges@gmail.com> >> > --- >> > drivers/input/touchscreen/wacom_w8001.c | 9 +++++++++ >> > 1 file changed, 9 insertions(+) >> > >> > diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c >> > index bab3c6a..c858200 100644 >> > --- a/drivers/input/touchscreen/wacom_w8001.c >> > +++ b/drivers/input/touchscreen/wacom_w8001.c >> > @@ -283,6 +283,15 @@ static irqreturn_t w8001_interrupt(struct serio *serio, >> > unsigned char tmp; >> > >> > w8001->data[w8001->idx] = data; >> > + >> > + /* ignore bogus idx values */ >> > + if (w8001->idx >= W8001_MAX_LENGTH) { >> > + pr_info("w8001: ignored interrupt: data 0x%02x idx %d\n", data, >> > + w8001->idx); >> > + w8001->idx = 0; >> > + return IRQ_HANDLED; >> > + } >> > + >> >> I don't have an x60t system to test with. I wonder if your system >> supports two finger touch or not. We at least have a bug in the code >> since W8001_MAX_LENGTH should be 13 instead of 11. How come no one had >> encountered that issue before? >> >> I'm going to email a patch to the list. Please test it and let us know >> your result. Maybe we still need your patch if your device doesn't >> support two finger touch or the idx=0xc can't be fixed by >> W8001_MAX_LENGTH=13. > > Just so we are clear this version of the patch is buggy as we check the > index only after [potentially] writing past the array bounds of > w8001->data[]. Thanks for the heads up. I noticed that last night. Since it breaks two-finger touch, we won't use it anyway. My other patch is still necessary though. You'll need to change: From: wacom <wacom@localhost.localdomain> to From: Ping Cheng <pingc@wacom.com> I made it on a brand new system, which I didn't setup the environment properly. I can update the patch if that's what you like... Ping -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c index bab3c6a..c858200 100644 --- a/drivers/input/touchscreen/wacom_w8001.c +++ b/drivers/input/touchscreen/wacom_w8001.c @@ -283,6 +283,15 @@ static irqreturn_t w8001_interrupt(struct serio *serio, unsigned char tmp; w8001->data[w8001->idx] = data; + + /* ignore bogus idx values */ + if (w8001->idx >= W8001_MAX_LENGTH) { + pr_info("w8001: ignored interrupt: data 0x%02x idx %d\n", data, + w8001->idx); + w8001->idx = 0; + return IRQ_HANDLED; + } + switch (w8001->idx++) { case 0: if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
I've noticed crashes when using my x60t using a coreboot bios. When using the pen I can produce a crash simply by tapping a few times. This generates an event which has an idx of 0xc. This in turn crashes the machine because the array access is greater than W8001_MAX_LENGTH. This patch checks for bogus values and filters them in order to prevent crashes. Signed-off-by: Chris J Arges <christopherarges@gmail.com> --- drivers/input/touchscreen/wacom_w8001.c | 9 +++++++++ 1 file changed, 9 insertions(+)