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| author | Johannes Berg <johannes@sipsolutions.net> | 2009-04-18 17:33:24 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-04-22 16:57:18 -0400 |
| commit | e7ec86f54e519e8e86f1cf328db13263f3ef8bd4 (patch) | |
| tree | 2b0a66930abf4ac710cc15120195c9259a0fcaba /net | |
| parent | ba44cb7226afd4e19308c1d8a90e8b7c566c0d8b (diff) | |
| download | linux-e7ec86f54e519e8e86f1cf328db13263f3ef8bd4.tar.gz linux-e7ec86f54e519e8e86f1cf328db13263f3ef8bd4.tar.bz2 linux-e7ec86f54e519e8e86f1cf328db13263f3ef8bd4.zip | |
mac80211: validate TIM IE length (redux)
The TIM IE must not be shorter than 4 bytes, so verify that
when parsing it and use the proper type. To ease that adjust
struct ieee80211_tim_ie to have a virtual bitmap of size
at least 1.
Also check that the TIM IE is actually present before trying
to parse it!
Because other people may need the function, make it a static
inline in ieee80211.h.
(The original "mac80211: validate TIM IE length" was a minimal fix for
2.6.30. This purports to be the full, correct fix. -- JWL)
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mac80211/ieee80211_i.h | 2 | ||||
| -rw-r--r-- | net/mac80211/mlme.c | 27 | ||||
| -rw-r--r-- | net/mac80211/util.c | 6 |
3 files changed, 7 insertions, 28 deletions
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index dba78d89a10c..1579bc92c88d 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -832,7 +832,7 @@ struct ieee802_11_elems { u8 *fh_params; u8 *ds_params; u8 *cf_params; - u8 *tim; + struct ieee80211_tim_ie *tim; u8 *ibss_params; u8 *challenge; u8 *wpa; diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 428742d7f440..1b0b7aa387ee 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -675,30 +675,6 @@ static void ieee80211_sta_wmm_params(struct ieee80211_local *local, } } -static bool ieee80211_check_tim(struct ieee802_11_elems *elems, u16 aid) -{ - u8 mask; - u8 index, indexn1, indexn2; - struct ieee80211_tim_ie *tim = (struct ieee80211_tim_ie *) elems->tim; - - if (unlikely(!tim || elems->tim_len < 4)) - return false; - - aid &= 0x3fff; - index = aid / 8; - mask = 1 << (aid & 7); - - indexn1 = tim->bitmap_ctrl & 0xfe; - indexn2 = elems->tim_len + indexn1 - 4; - - if (index < indexn1 || index > indexn2) - return false; - - index -= indexn1; - - return !!(tim->virtual_map[index] & mask); -} - static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata, u16 capab, bool erp_valid, u8 erp) { @@ -1806,7 +1782,8 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, care_about_ies, ncrc); if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) - directed_tim = ieee80211_check_tim(&elems, ifmgd->aid); + directed_tim = ieee80211_check_tim(elems.tim, elems.tim_len, + ifmgd->aid); ncrc = crc32_be(ncrc, (void *)&directed_tim, sizeof(directed_tim)); diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 11244212f41d..61876eb50b49 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -588,8 +588,10 @@ u32 ieee802_11_parse_elems_crc(u8 *start, size_t len, elems->cf_params_len = elen; break; case WLAN_EID_TIM: - elems->tim = pos; - elems->tim_len = elen; + if (elen >= sizeof(struct ieee80211_tim_ie)) { + elems->tim = (void *)pos; + elems->tim_len = elen; + } break; case WLAN_EID_IBSS_PARAMS: elems->ibss_params = pos; |