From 8bfb3676606454ffec836f56c5dc3e69dfc0956a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 14 Jun 2017 09:17:38 +0200 Subject: wireless: wext: remove ndo_do_ioctl fallback There are no longer any drivers (in the tree proper, I didn't check all the staging drivers) that take WEXT ioctls through this API, the only remaining ones that even have ndo_do_ioctl are using it only for private ioctls. Therefore, we can remove this call. Signed-off-by: Johannes Berg --- net/wireless/wext-core.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'net') diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index 1a4db6790e20..24ba8a99b946 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -957,9 +957,6 @@ static int wireless_process_ioctl(struct net *net, struct ifreq *ifr, else if (private) return private(dev, iwr, cmd, info, handler); } - /* Old driver API : call driver ioctl handler */ - if (dev->netdev_ops->ndo_do_ioctl) - return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd); return -EOPNOTSUPP; } -- cgit From 4f39a1f5870104b1670df2c09c831ac281896545 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 14 Jun 2017 09:21:58 +0200 Subject: wireless: wext: use struct iwreq earlier in the call chain To make it clear that we never use struct ifreq, cast from it directly in the wext entrypoint and use struct iwreq from there on. The next patch will remove the cast again and pass the correct struct from the beginning. Signed-off-by: Johannes Berg --- net/wireless/wext-core.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index 24ba8a99b946..12949c8d3e5f 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -914,13 +914,12 @@ int call_commit_handler(struct net_device *dev) * Main IOCTl dispatcher. * Check the type of IOCTL and call the appropriate wrapper... */ -static int wireless_process_ioctl(struct net *net, struct ifreq *ifr, +static int wireless_process_ioctl(struct net *net, struct iwreq *iwr, unsigned int cmd, struct iw_request_info *info, wext_ioctl_func standard, wext_ioctl_func private) { - struct iwreq *iwr = (struct iwreq *) ifr; struct net_device *dev; iw_handler handler; @@ -928,7 +927,7 @@ static int wireless_process_ioctl(struct net *net, struct ifreq *ifr, * The copy_to/from_user() of ifr is also dealt with in there */ /* Make sure the device exist */ - if ((dev = __dev_get_by_name(net, ifr->ifr_name)) == NULL) + if ((dev = __dev_get_by_name(net, iwr->ifr_name)) == NULL) return -ENODEV; /* A bunch of special cases, then the generic case... @@ -974,7 +973,7 @@ static int wext_permission_check(unsigned int cmd) } /* entry point from dev ioctl */ -static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr, +static int wext_ioctl_dispatch(struct net *net, struct iwreq *iwr, unsigned int cmd, struct iw_request_info *info, wext_ioctl_func standard, wext_ioctl_func private) @@ -984,9 +983,9 @@ static int wext_ioctl_dispatch(struct net *net, struct ifreq *ifr, if (ret) return ret; - dev_load(net, ifr->ifr_name); + dev_load(net, iwr->ifr_name); rtnl_lock(); - ret = wireless_process_ioctl(net, ifr, cmd, info, standard, private); + ret = wireless_process_ioctl(net, iwr, cmd, info, standard, private); rtnl_unlock(); return ret; @@ -1042,7 +1041,7 @@ int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd, struct iw_request_info info = { .cmd = cmd, .flags = 0 }; int ret; - ret = wext_ioctl_dispatch(net, ifr, cmd, &info, + ret = wext_ioctl_dispatch(net, (void *)ifr, cmd, &info, ioctl_standard_call, ioctl_private_call); if (ret >= 0 && @@ -1104,7 +1103,7 @@ int compat_wext_handle_ioctl(struct net *net, unsigned int cmd, info.cmd = cmd; info.flags = IW_REQUEST_FLAG_COMPAT; - ret = wext_ioctl_dispatch(net, (struct ifreq *) &iwr, cmd, &info, + ret = wext_ioctl_dispatch(net, &iwr, cmd, &info, compat_standard_call, compat_private_call); -- cgit From 68dd02d19c811ca8ea60220a9d73e13b4bdad73a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 14 Jun 2017 09:28:11 +0200 Subject: dev_ioctl: copy only the smaller struct iwreq for wext Unfortunately, struct iwreq isn't a proper subset of struct ifreq, but is still handled by the same code path. Robert reported that then applications may (randomly) fault if the struct iwreq they pass happens to land within 8 bytes of the end of a mapping (the struct is only 32 bytes, vs. struct ifreq's 40 bytes). To fix this, pull out the code handling wireless extension ioctls and copy only the smaller structure in this case. This bug goes back a long time, I tracked that it was introduced into mainline in 2.1.15, over 20 years ago! This fixes https://bugzilla.kernel.org/show_bug.cgi?id=195869 Reported-by: Robert O'Callahan Signed-off-by: Johannes Berg --- net/core/dev_ioctl.c | 19 ++++++++++++++++--- net/wireless/wext-core.c | 6 +++--- 2 files changed, 19 insertions(+), 6 deletions(-) (limited to 'net') diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index b94b1d293506..27fad31784a8 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -410,6 +410,22 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg) if (cmd == SIOCGIFNAME) return dev_ifname(net, (struct ifreq __user *)arg); + /* + * Take care of Wireless Extensions. Unfortunately struct iwreq + * isn't a proper subset of struct ifreq (it's 8 byte shorter) + * so we need to treat it specially, otherwise applications may + * fault if the struct they're passing happens to land at the + * end of a mapped page. + */ + if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) { + struct iwreq iwr; + + if (copy_from_user(&iwr, arg, sizeof(iwr))) + return -EFAULT; + + return wext_handle_ioctl(net, &iwr, cmd, arg); + } + if (copy_from_user(&ifr, arg, sizeof(struct ifreq))) return -EFAULT; @@ -559,9 +575,6 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg) ret = -EFAULT; return ret; } - /* Take care of Wireless Extensions */ - if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) - return wext_handle_ioctl(net, &ifr, cmd, arg); return -ENOTTY; } } diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index 12949c8d3e5f..6cdb054484d6 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -1035,18 +1035,18 @@ static int ioctl_standard_call(struct net_device * dev, } -int wext_handle_ioctl(struct net *net, struct ifreq *ifr, unsigned int cmd, +int wext_handle_ioctl(struct net *net, struct iwreq *iwr, unsigned int cmd, void __user *arg) { struct iw_request_info info = { .cmd = cmd, .flags = 0 }; int ret; - ret = wext_ioctl_dispatch(net, (void *)ifr, cmd, &info, + ret = wext_ioctl_dispatch(net, iwr, cmd, &info, ioctl_standard_call, ioctl_private_call); if (ret >= 0 && IW_IS_GET(cmd) && - copy_to_user(arg, ifr, sizeof(struct iwreq))) + copy_to_user(arg, iwr, sizeof(struct iwreq))) return -EFAULT; return ret; -- cgit