[PATCH 4.14 007/159] mac80211_hwsim: validate number of different channels

From: Greg Kroah-Hartman
Date: Fri Feb 23 2018 - 13:50:52 EST


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

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

From: Johannes Berg <johannes.berg@xxxxxxxxx>

commit 51a1aaa631c90223888d8beac4d649dc11d2ca55 upstream.

When creating a new radio on the fly, hwsim allows this
to be done with an arbitrary number of channels, but
cfg80211 only supports a limited number of simultaneous
channels, leading to a warning.

Fix this by validating the number - this requires moving
the define for the maximum out to a visible header file.

Reported-by: syzbot+8dd9051ff19940290931@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b59ec8dd4394 ("mac80211_hwsim: fix number of channels in interface combinations")
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/mac80211_hwsim.c | 5 +++++
include/net/cfg80211.h | 2 ++
net/wireless/core.h | 2 --
3 files changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -3119,6 +3119,11 @@ static int hwsim_new_radio_nl(struct sk_
if (info->attrs[HWSIM_ATTR_CHANNELS])
param.channels = nla_get_u32(info->attrs[HWSIM_ATTR_CHANNELS]);

+ if (param.channels > CFG80211_MAX_NUM_DIFFERENT_CHANNELS) {
+ GENL_SET_ERR_MSG(info, "too many channels specified");
+ return -EINVAL;
+ }
+
if (info->attrs[HWSIM_ATTR_NO_VIF])
param.no_vif = true;

--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -815,6 +815,8 @@ struct cfg80211_csa_settings {
u8 count;
};

+#define CFG80211_MAX_NUM_DIFFERENT_CHANNELS 10
+
/**
* struct iface_combination_params - input parameters for interface combinations
*
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -502,8 +502,6 @@ void cfg80211_stop_p2p_device(struct cfg
void cfg80211_stop_nan(struct cfg80211_registered_device *rdev,
struct wireless_dev *wdev);

-#define CFG80211_MAX_NUM_DIFFERENT_CHANNELS 10
-
#ifdef CONFIG_CFG80211_DEVELOPER_WARNINGS
#define CFG80211_DEV_WARN_ON(cond) WARN_ON(cond)
#else