In 'cfg80211_wext_siwscan()', add extra check whether number of channels passed via 'ioctl(sock, SIOCSIWSCAN, ...)' doesn't exceed IW_MAX_FREQUENCIES and reject invalid request with -EINVAL otherwise. Reported-by: syzbot+253cd2d2491df77c93ac@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=253cd2d2491df77c93ac Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx> --- net/wireless/scan.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 127853877a0a..6d4d3447aecc 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -3400,10 +3400,14 @@ int cfg80211_wext_siwscan(struct net_device *dev, wiphy = &rdev->wiphy; /* Determine number of channels, needed to allocate creq */ - if (wreq && wreq->num_channels) + if (wreq && wreq->num_channels) { + /* Passed from userspace so should be checked */ + if (unlikely(wreq->num_channels > IW_MAX_FREQUENCIES)) + return -EINVAL; n_channels = wreq->num_channels; - else + } else { n_channels = ieee80211_get_num_supported_channels(wiphy); + } creq = kzalloc(sizeof(*creq) + sizeof(struct cfg80211_ssid) + n_channels * sizeof(void *), -- 2.45.1
