From b9bbc4c1debc837ba56872fb3b2499ba6459ca8b Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Mon, 13 Sep 2021 21:58:26 +0200 Subject: [PATCH] ethtool: prevent endless loop if eeprom size is smaller than announced It shouldn't happen, but can happen that readable eeprom size is smaller than announced. Then we would be stuck in an endless loop here because after reaching the actual end reads return eeprom.len = 0. I faced this issue when making a mistake in driver development. Detect this scenario and return an error. Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- net/ethtool/ioctl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index f2abc31..999e2a6 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -1537,6 +1537,10 @@ static int ethtool_get_any_eeprom(struct net_device *dev, void __user *useraddr, ret = getter(dev, &eeprom, data); if (ret) break; + if (!eeprom.len) { + ret = -EIO; + break; + } if (copy_to_user(userbuf, data, eeprom.len)) { ret = -EFAULT; break; -- 2.7.4