| Message ID | 20210428063941.105161-1-ducheng2@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | net:wireless: call cfg80211_leave_ocb when switching between ADHOC and OCB | expand |
diff --git a/net/wireless/util.c b/net/wireless/util.c index 1bf0200f562a..f424ac7633bb 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -1056,6 +1056,9 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev, case NL80211_IFTYPE_MESH_POINT: /* mesh should be handled? */ break; + case NL80211_IFTYPE_OCB: + cfg80211_leave_ocb(rdev, dev); + break; default: break; }
If the userland switches back-and-forth between NL80211_IFTYPE_OCB and NL80211_IFTYPE_ADHOC via send_msg(NL80211_CMD_SET_INTERFACE), there is a chance where the cleanup cfg80211_leave_ocb() is not called. This leads to initialization of in-use memory (e.g. init u.ibss while in-use by u.ocb) due to a shared struct/union within ieee80211_sub_if_data: struct ieee80211_sub_if_data { ... union { struct ieee80211_if_ap ap; struct ieee80211_if_vlan vlan; struct ieee80211_if_managed mgd; struct ieee80211_if_ibss ibss; // <- shares address struct ieee80211_if_mesh mesh; struct ieee80211_if_ocb ocb; // <- shares address struct ieee80211_if_mntr mntr; struct ieee80211_if_nan nan; } u; ... } Therefore add handling of otype == NL80211_IFTYPE_OCB, during cfg80211_change_iface() to perform cleanup when leaving OCB mode. link to syzkaller bug: https://syzkaller.appspot.com/bug?id=0612dbfa595bf4b9b680ff7b4948257b8e3732d5 Reported-by: syzbot+105896fac213f26056f9@syzkaller.appspotmail.com Signed-off-by: Du Cheng <ducheng2@gmail.com> --- Reproducible steps: 1. NL80211_CMD_SET_INTERFACE: NL80211_IFTYPE_ADHOC // set IBSS mode 2. NL80211_CMD_SET_INTERFACE: NL80211_IFTYPE_OCB // switch to OCB mode, calls ieee80211_ocb_setup_sdata, init u.ocb.housekeeping_timer 3. NL80211_CMD_JOIN_OCB 4. NL80211_CMD_SET_INTERFACE: NL80211_IFTYPE_ADHOC // swtich to IBSS mode without calling NL80211_CMD_LEAVE_OCB, // leaving u.ocb.housekeeping_timer NOT destroyed 5. entering IBSS mode, kernel panic while initializing u.ibss.timer, an active debug_object as &u.ibss.timer == &u.ocb.housekeeping_timer net/wireless/util.c | 3 +++ 1 file changed, 3 insertions(+)