[PATCH -next v3 1/2] posix-timers: Check timespec64 before call clock_set()

[Jinjie Ruan]

As Andrew pointed out, it will make sense that the PTP core
checked timespec64 struct's tv_sec and tv_nsec range before calling
ptp->info->settime64(). Check it ahead in more higher layer
clock_settime() as Richard suggested.

There are some drivers that use tp->tv_sec and tp->tv_nsec directly to
write registers without validity checks and assume that the higher layer
has checked it, which is dangerous and will benefit from this, such as
hclge_ptp_settime(), igb_ptp_settime_i210(), _rcar_gen4_ptp_settime(),
and some drivers can remove the checks of itself.

Suggested-by: Richard Cochran <richardcochran@xxxxxxxxx>
Suggested-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
v3:
- Adjust to check in more higher layer clock_settime().
- Remove the NULL check.
- Update the commit message and subject.
v2:
- Adjust to check in ptp_clock_settime().
---
 kernel/time/posix-timers.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 1cc830ef93a7..34deec619e17 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1137,6 +1137,9 @@ SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
 	if (get_timespec64(&new_tp, tp))
 		return -EFAULT;
 
+	if (!timespec64_valid(&new_tp))
+		return -ERANGE;
+
 	/*
 	 * Permission checks have to be done inside the clock specific
 	 * setter callback.
-- 
2.34.1