diff options
| author | Du Cheng <ducheng2@gmail.com> | 2021-05-10 12:16:49 +0800 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2021-05-31 21:39:10 +0200 |
| commit | e298aa358f0ca658406d524b6639fe389cb6e11e (patch) | |
| tree | b2e85597f417c85427254241077919472b53bf17 | |
| parent | b90f51e8e1f5014c01c82a7bf4c611643d0a8bcb (diff) | |
| download | lwn-e298aa358f0ca658406d524b6639fe389cb6e11e.tar.gz lwn-e298aa358f0ca658406d524b6639fe389cb6e11e.zip | |
mac80211: fix skb length check in ieee80211_scan_rx()
Replace hard-coded compile-time constants for header length check
with dynamic determination based on the frame type. Otherwise, we
hit a validation WARN_ON in cfg80211 later.
Fixes: cd418ba63f0c ("mac80211: convert S1G beacon to scan results")
Reported-by: syzbot+405843667e93b9790fc1@syzkaller.appspotmail.com
Signed-off-by: Du Cheng <ducheng2@gmail.com>
Link: https://lore.kernel.org/r/20210510041649.589754-1-ducheng2@gmail.com
[style fixes, reword commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | net/mac80211/scan.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index d4cc9ac2d703..6b50cb5e0e3c 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -251,13 +251,24 @@ void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb) struct ieee80211_mgmt *mgmt = (void *)skb->data; struct ieee80211_bss *bss; struct ieee80211_channel *channel; + size_t min_hdr_len = offsetof(struct ieee80211_mgmt, + u.probe_resp.variable); + + if (!ieee80211_is_probe_resp(mgmt->frame_control) && + !ieee80211_is_beacon(mgmt->frame_control) && + !ieee80211_is_s1g_beacon(mgmt->frame_control)) + return; if (ieee80211_is_s1g_beacon(mgmt->frame_control)) { - if (skb->len < 15) - return; - } else if (skb->len < 24 || - (!ieee80211_is_probe_resp(mgmt->frame_control) && - !ieee80211_is_beacon(mgmt->frame_control))) + if (ieee80211_is_s1g_short_beacon(mgmt->frame_control)) + min_hdr_len = offsetof(struct ieee80211_ext, + u.s1g_short_beacon.variable); + else + min_hdr_len = offsetof(struct ieee80211_ext, + u.s1g_beacon); + } + + if (skb->len < min_hdr_len) return; sdata1 = rcu_dereference(local->scan_sdata); |