| Message ID | 20250301111053.2661-1-v.shevtsov@mt-integration.ru (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | media: cec: avoid wraparound in timer interval calculation | expand |
Le 01/03/2025 à 12:09, Vitaliy Shevtsov a écrit : > [Why] > The timer function code may have an integer wraparound issue. Since both > pin->tx_custom_low_usecs and pin->tx_custom_high_usecs can be set to up to > 9999999 from the user space via cec_pin_error_inj_parse_line(), this may > cause usecs to be overflowed when adap->monitor_pin_cnt is zero and usecs > is multiplied by 1000. > > [How] > Fix this by casting usecs to u64 when it is being converted from > microseconds to nanoseconds. > > Found by Linux Verification Center (linuxtesting.org) with Svace. > > Fixes: 865463fc03ed ("media: cec-pin: add error injection support") > Signed-off-by: Vitaliy Shevtsov <v.shevtsov@mt-integration.ru> > --- > drivers/media/cec/core/cec-pin.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c > index a70451d99ebc..f15ed5c67a65 100644 > --- a/drivers/media/cec/core/cec-pin.c > +++ b/drivers/media/cec/core/cec-pin.c > @@ -1021,7 +1021,7 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) > pin->wait_usecs = 0; > pin->timer_ts = ktime_add_us(ts, usecs); > hrtimer_forward_now(timer, > - ns_to_ktime(usecs * 1000)); > + ns_to_ktime((u64)usecs * 1000)); Or maybe us_to_ktime() to be less verbose? CJ > return HRTIMER_RESTART; > } > pin->wait_usecs = usecs - 100;
On Sat, 1 Mar 2025 12:32:30 +0100, Christophe JAILLET wrote: > Le 01/03/2025 à 12:09, Vitaliy Shevtsov a écrit : > > [Why] > > The timer function code may have an integer wraparound issue. Since both > > pin->tx_custom_low_usecs and pin->tx_custom_high_usecs can be set to up to > > 9999999 from the user space via cec_pin_error_inj_parse_line(), this may > > cause usecs to be overflowed when adap->monitor_pin_cnt is zero and usecs > > is multiplied by 1000. > > > > [How] > > Fix this by casting usecs to u64 when it is being converted from > > microseconds to nanoseconds. > > > > Found by Linux Verification Center (linuxtesting.org) with Svace. > > > > Fixes: 865463fc03ed ("media: cec-pin: add error injection support") > > Signed-off-by: Vitaliy Shevtsov <v.shevtsov@mt-integration.ru> > > --- > > drivers/media/cec/core/cec-pin.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c > > index a70451d99ebc..f15ed5c67a65 100644 > > --- a/drivers/media/cec/core/cec-pin.c > > +++ b/drivers/media/cec/core/cec-pin.c > > @@ -1021,7 +1021,7 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) > > pin->wait_usecs = 0; > > pin->timer_ts = ktime_add_us(ts, usecs); > > hrtimer_forward_now(timer, > > - ns_to_ktime(usecs * 1000)); > > + ns_to_ktime((u64)usecs * 1000)); > > Or maybe us_to_ktime() to be less verbose? > > CJ > That makes sense but let me check first. I will send a new one soon. > > return HRTIMER_RESTART; > > } > > pin->wait_usecs = usecs - 100; >
diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c index a70451d99ebc..f15ed5c67a65 100644 --- a/drivers/media/cec/core/cec-pin.c +++ b/drivers/media/cec/core/cec-pin.c @@ -1021,7 +1021,7 @@ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) pin->wait_usecs = 0; pin->timer_ts = ktime_add_us(ts, usecs); hrtimer_forward_now(timer, - ns_to_ktime(usecs * 1000)); + ns_to_ktime((u64)usecs * 1000)); return HRTIMER_RESTART; } pin->wait_usecs = usecs - 100;
[Why] The timer function code may have an integer wraparound issue. Since both pin->tx_custom_low_usecs and pin->tx_custom_high_usecs can be set to up to 9999999 from the user space via cec_pin_error_inj_parse_line(), this may cause usecs to be overflowed when adap->monitor_pin_cnt is zero and usecs is multiplied by 1000. [How] Fix this by casting usecs to u64 when it is being converted from microseconds to nanoseconds. Found by Linux Verification Center (linuxtesting.org) with Svace. Fixes: 865463fc03ed ("media: cec-pin: add error injection support") Signed-off-by: Vitaliy Shevtsov <v.shevtsov@mt-integration.ru> --- drivers/media/cec/core/cec-pin.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)