[PATCH 4.9 018/145] staging: android: ion: Switch from WARN to pr_warn

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Laura Abbott <labbott@xxxxxxxxxx>

commit e4e179a844f52e907e550f887d0a2171f1508af1 upstream.

Syzbot reported a warning with Ion:

WARNING: CPU: 0 PID: 3502 at drivers/staging/android/ion/ion-ioctl.c:73 ion_ioctl+0x2db/0x380 drivers/staging/android/ion/ion-ioctl.c:73
Kernel panic - not syncing: panic_on_warn set ...

This is a warning that validation of the ioctl fields failed. This was
deliberately added as a warning to make it very obvious to developers that
something needed to be fixed. In reality, this is overkill and disturbs
fuzzing. Switch to pr_warn for a message instead.

Reported-by: syzbot+fa2d5f63ee5904a0115a@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/staging/android/ion/ion-ioctl.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/staging/android/ion/ion-ioctl.c
+++ b/drivers/staging/android/ion/ion-ioctl.c
@@ -83,8 +83,10 @@ long ion_ioctl(struct file *filp, unsign
 		return -EFAULT;
 
 	ret = validate_ioctl_arg(cmd, &data);
-	if (WARN_ON_ONCE(ret))
+	if (ret) {
+		pr_warn_once("%s: ioctl validate failed\n", __func__);
 		return ret;
+	}
 
 	if (!(dir & _IOC_WRITE))
 		memset(&data, 0, sizeof(data));