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| author | Johannes Berg <johannes.berg@intel.com> | 2020-05-26 14:33:48 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2020-05-27 10:03:27 +0200 |
| commit | c11299243370580832c27882dcedf2604f9f48f8 (patch) | |
| tree | 94a67d89f92811c30c8b309fc186e9fe68c1a03e /net/mac80211 | |
| parent | 1b9ae0c92925ac40489be526d67d0010d0724ce0 (diff) | |
| download | linux-c11299243370580832c27882dcedf2604f9f48f8.tar.gz linux-c11299243370580832c27882dcedf2604f9f48f8.tar.bz2 linux-c11299243370580832c27882dcedf2604f9f48f8.zip | |
mac80211: fix HT-Control field reception for management frames
If we receive management frames with an HT-Control field, we cannot
parse them properly, as we assume a fixed length management header.
Since we don't even need the HTC field (for these frames, or really
at all), just remove it at the beginning of RX.
Reported-by: Haggai Abramovsky <haggai.abramovsky@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200526143346.cf5ce70521c5.I333251a084ec4cfe67b7ef7efe2d2f1a33883931@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211')
| -rw-r--r-- | net/mac80211/rx.c | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 8b0fa5e345f4..21854a61a2b7 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -93,13 +93,44 @@ static u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len, * This function cleans up the SKB, i.e. it removes all the stuff * only useful for monitoring. */ -static void remove_monitor_info(struct sk_buff *skb, - unsigned int present_fcs_len, - unsigned int rtap_space) +static struct sk_buff *ieee80211_clean_skb(struct sk_buff *skb, + unsigned int present_fcs_len, + unsigned int rtap_space) { + struct ieee80211_hdr *hdr; + unsigned int hdrlen; + __le16 fc; + if (present_fcs_len) __pskb_trim(skb, skb->len - present_fcs_len); __pskb_pull(skb, rtap_space); + + hdr = (void *)skb->data; + fc = hdr->frame_control; + + /* + * Remove the HT-Control field (if present) on management + * frames after we've sent the frame to monitoring. We + * (currently) don't need it, and don't properly parse + * frames with it present, due to the assumption of a + * fixed management header length. + */ + if (likely(!ieee80211_is_mgmt(fc) || !ieee80211_has_order(fc))) + return skb; + + hdrlen = ieee80211_hdrlen(fc); + hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_ORDER); + + if (!pskb_may_pull(skb, hdrlen)) { + dev_kfree_skb(skb); + return NULL; + } + + memmove(skb->data + IEEE80211_HT_CTL_LEN, skb->data, + hdrlen - IEEE80211_HT_CTL_LEN); + __pskb_pull(skb, IEEE80211_HT_CTL_LEN); + + return skb; } static inline bool should_drop_frame(struct sk_buff *skb, int present_fcs_len, @@ -827,8 +858,8 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, return NULL; } - remove_monitor_info(origskb, present_fcs_len, rtap_space); - return origskb; + return ieee80211_clean_skb(origskb, present_fcs_len, + rtap_space); } ieee80211_handle_mu_mimo_mon(monitor_sdata, origskb, rtap_space); @@ -871,8 +902,7 @@ ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb, if (!origskb) return NULL; - remove_monitor_info(origskb, present_fcs_len, rtap_space); - return origskb; + return ieee80211_clean_skb(origskb, present_fcs_len, rtap_space); } static void ieee80211_parse_qos(struct ieee80211_rx_data *rx) |