4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg <johannes.berg@xxxxxxxxx> [ Upstream commit 484004339d4514fde425f6e8a9f6a6cc979bb0c3 ] Syzbot continues to try to create mac80211_hwsim radios, and manages to pass parameters that are later checked with WARN_ON in cfg80211 - catch another one in hwsim directly. Reported-by: syzbot+2a12f11c306afe871c1f@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/mac80211_hwsim.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3194,6 +3194,11 @@ 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 < 1) { + GENL_SET_ERR_MSG(info, "must have at least one channel"); + return -EINVAL; + } + if (param.channels > CFG80211_MAX_NUM_DIFFERENT_CHANNELS) { GENL_SET_ERR_MSG(info, "too many channels specified"); return -EINVAL;