From c72d2b916be9c65e65c16056f1a6dccb6fe39b97 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 24 Mar 2021 18:11:57 -0700 Subject: [PATCH] ethtool: fec: sanitize ethtool_fecparam->reserved struct ethtool_fecparam::reserved is never looked at by the core. Make sure it's actually 0. Unfortunately we can't return an error because old ethtool doesn't zero-initialize the structure for SET. On GET we can be more verbose, there are no in tree (ab)users. Fix up the kdoc on the structure. Remove the mention of FEC bypass. Seems like a niche thing to configure in the first place. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: hongrongxuan --- include/uapi/linux/ethtool.h | 2 +- net/ethtool/ioctl.c | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index 19c4f5966738..f4f23c3446c4 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -1378,7 +1378,7 @@ struct ethtool_per_queue_op { * @cmd: Command number = %ETHTOOL_GFECPARAM or %ETHTOOL_SFECPARAM * @active_fec: FEC mode which is active on the port * @fec: Bitmask of supported/configured FEC modes - * @rsvd: Reserved for future extensions. i.e FEC bypass feature. + * @reserved: Reserved for future extensions, ignore on GET, write 0 for SET. */ struct ethtool_fecparam { __u32 cmd; diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c index d2c7ad494a9f..a307506aa3ff 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -2491,6 +2491,9 @@ static int ethtool_get_fecparam(struct net_device *dev, void __user *useraddr) if (rc) return rc; + if (WARN_ON_ONCE(fecparam.reserved)) + fecparam.reserved = 0; + if (copy_to_user(useraddr, &fecparam, sizeof(fecparam))) return -EFAULT; return 0; @@ -2506,6 +2509,8 @@ static int ethtool_set_fecparam(struct net_device *dev, void __user *useraddr) if (copy_from_user(&fecparam, useraddr, sizeof(fecparam))) return -EFAULT; + fecparam.reserved = 0; + return dev->ethtool_ops->set_fecparam(dev, &fecparam); }