diff options
| author | Christian Lamparter <chunkeey@googlemail.com> | 2010-10-08 22:27:07 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2010-10-11 15:04:20 -0400 |
| commit | d12c74528e3065c90df70fbc06ec6ffd6e804738 (patch) | |
| tree | 623743ffa8899178b4cb4cfe7c831918f6727e74 /net/mac80211/mesh_plink.c | |
| parent | 7109ca5c80a0bb94378ebd7f8bb6d00edb5e6fba (diff) | |
| download | lwn-d12c74528e3065c90df70fbc06ec6ffd6e804738.tar.gz lwn-d12c74528e3065c90df70fbc06ec6ffd6e804738.zip | |
mac80211: fix possible null-pointer de-reference
This patch not only fixes a null-pointer de-reference
that would be triggered by a PLINK_OPEN frame with mis-
matching/incompatible mesh configuration, but also
responds correctly to non-compatible PLINK_OPEN frames
by generating a PLINK_CLOSE with the right reason code.
The original bug was detected by smatch.
( http://repo.or.cz/w/smatch.git )
net/mac80211/mesh_plink.c +574 mesh_rx_plink_frame(168)
error: we previously assumed 'sta' could be null.
Cc: <stable@kernel.org>
Reviewed-and-Tested-by: Steve deRosier <steve@cozybit.com>
Reviewed-and-Tested-by: Javier Cardona <javier@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/mesh_plink.c')
| -rw-r--r-- | net/mac80211/mesh_plink.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c index ea13a80a476c..1c91f0f3c307 100644 --- a/net/mac80211/mesh_plink.c +++ b/net/mac80211/mesh_plink.c @@ -412,7 +412,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m enum plink_event event; enum plink_frame_type ftype; size_t baselen; - bool deactivated; + bool deactivated, matches_local = true; u8 ie_len; u8 *baseaddr; __le16 plid, llid, reason; @@ -487,6 +487,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m /* Now we will figure out the appropriate event... */ event = PLINK_UNDEFINED; if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) { + matches_local = false; switch (ftype) { case PLINK_OPEN: event = OPN_RJCT; @@ -498,7 +499,15 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m /* avoid warning */ break; } - spin_lock_bh(&sta->lock); + } + + if (!sta && !matches_local) { + rcu_read_unlock(); + reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION); + llid = 0; + mesh_plink_frame_tx(sdata, PLINK_CLOSE, mgmt->sa, llid, + plid, reason); + return; } else if (!sta) { /* ftype == PLINK_OPEN */ u32 rates; @@ -522,7 +531,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m } event = OPN_ACPT; spin_lock_bh(&sta->lock); - } else { + } else if (matches_local) { spin_lock_bh(&sta->lock); switch (ftype) { case PLINK_OPEN: @@ -564,6 +573,8 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m rcu_read_unlock(); return; } + } else { + spin_lock_bh(&sta->lock); } mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n", |