From 240e114411e74d2ee8121643e0c67717eb7c6982 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 --- 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 36bf435..9e2682a 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -1380,7 +1380,7 @@ 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 0788cc3..be35490 100644 --- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -2568,6 +2568,9 @@ 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; @@ -2583,6 +2586,8 @@ 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); } -- 2.7.4