This is a note to let you know that I've just added the patch titled batman-adv: protect tt_local_entry from concurrent delete events to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: batman-adv-protect-tt_local_entry-from-concurrent-delete-events.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ef72706a0543d0c3a5ab29bd6378fdfb368118d9 Mon Sep 17 00:00:00 2001 From: Marek Lindner <mareklindner@xxxxxxxxxxxxx> Date: Wed, 17 Jun 2015 20:01:36 +0800 Subject: batman-adv: protect tt_local_entry from concurrent delete events From: Marek Lindner <mareklindner@xxxxxxxxxxxxx> commit ef72706a0543d0c3a5ab29bd6378fdfb368118d9 upstream. The tt_local_entry deletion performed in batadv_tt_local_remove() was neither protecting against simultaneous deletes nor checking whether the element was still part of the list before calling hlist_del_rcu(). Replacing the hlist_del_rcu() call with batadv_hash_remove() provides adequate protection via hash spinlocks as well as an is-element-still-in-hash check to avoid 'blind' hash removal. Fixes: 068ee6e204e1 ("batman-adv: roaming handling mechanism redesign") Reported-by: alfonsname@xxxxxx Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx> Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/batman-adv/translation-table.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -1018,6 +1018,7 @@ uint16_t batadv_tt_local_remove(struct b struct batadv_tt_local_entry *tt_local_entry; uint16_t flags, curr_flags = BATADV_NO_FLAGS; struct batadv_softif_vlan *vlan; + void *tt_entry_exists; tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid); if (!tt_local_entry) @@ -1045,7 +1046,15 @@ uint16_t batadv_tt_local_remove(struct b * immediately purge it */ batadv_tt_local_event(bat_priv, tt_local_entry, BATADV_TT_CLIENT_DEL); - hlist_del_rcu(&tt_local_entry->common.hash_entry); + + tt_entry_exists = batadv_hash_remove(bat_priv->tt.local_hash, + batadv_compare_tt, + batadv_choose_tt, + &tt_local_entry->common); + if (!tt_entry_exists) + goto out; + + /* extra call to free the local tt entry */ batadv_tt_local_entry_free_ref(tt_local_entry); /* decrease the reference held for this vlan */ Patches currently in stable-queue which might be from mareklindner@xxxxxxxxxxxxx are queue-4.1/batman-adv-fix-kernel-crash-due-to-missing-null-checks.patch queue-4.1/batman-adv-make-dat-capability-changes-atomic.patch queue-4.1/batman-adv-protect-tt_local_entry-from-concurrent-delete-events.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html