[PATCH AUTOSEL 4.20 036/304] ptp: check gettime64 return code in PTP_SYS_OFFSET ioctl

From: Sasha Levin
Date: Mon Jan 28 2019 - 10:44:58 EST


From: Miroslav Lichvar <mlichvar@xxxxxxxxxx>

[ Upstream commit 83d0bdc7390b890905634186baaa294475cd6a06 ]

If a gettime64 call fails, return the error and avoid copying data back
to user.

Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Signed-off-by: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/ptp/ptp_chardev.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 2012551d93e0..796eeffdf93b 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -228,7 +228,9 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
pct->sec = ts.tv_sec;
pct->nsec = ts.tv_nsec;
pct++;
- ptp->info->gettime64(ptp->info, &ts);
+ err = ptp->info->gettime64(ptp->info, &ts);
+ if (err)
+ goto out;
pct->sec = ts.tv_sec;
pct->nsec = ts.tv_nsec;
pct++;
@@ -281,6 +283,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
break;
}

+out:
kfree(sysoff);
return err;
}
--
2.19.1