This is a note to let you know that I've just added the patch titled batman-adv: Avoid WARN_ON timing related checks to the 4.4-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-avoid-warn_on-timing-related-checks.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Nov 23 01:39:02 PM CET 2021 From: Sven Eckelmann <sven@xxxxxxxxxxxxx> Date: Sat, 20 Nov 2021 13:39:39 +0100 Subject: batman-adv: Avoid WARN_ON timing related checks To: stable@xxxxxxxxxxxxxxx Cc: b.a.t.m.a.n@xxxxxxxxxxxxxxxxxxx, Sven Eckelmann <sven@xxxxxxxxxxxxx>, Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>, syzbot+c0b807de416427ff3dd1@xxxxxxxxxxxxxxxxxxxxxxxxx, Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx> Message-ID: <20211120123939.260723-12-sven@xxxxxxxxxxxxx> From: Sven Eckelmann <sven@xxxxxxxxxxxxx> commit 9f460ae31c4435fd022c443a6029352217a16ac1 upstream. The soft/batadv interface for a queued OGM can be changed during the time the OGM was queued for transmission and when the OGM is actually transmitted by the worker. But WARN_ON must be used to denote kernel bugs and not to print simple warnings. A warning can simply be printed using pr_warn. Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Reported-by: syzbot+c0b807de416427ff3dd1@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: ef0a937f7a14 ("batman-adv: consider outgoing interface in OGM sending") Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx> Signed-off-by: Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx> [ bp: 4.4 backported: adjust context. ] Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/batman-adv/bat_iv_ogm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -526,8 +526,10 @@ static void batadv_iv_ogm_emit(struct ba if (WARN_ON(!forw_packet->if_outgoing)) goto out; - if (WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface)) + if (forw_packet->if_outgoing->soft_iface != soft_iface) { + pr_warn("%s: soft interface switch for queued OGM\n", __func__); goto out; + } if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE) goto out; Patches currently in stable-queue which might be from sven@xxxxxxxxxxxxx are queue-4.4/batman-adv-consider-fragmentation-for-needed_headroom.patch queue-4.4/ath9k-fix-potential-interrupt-storm-on-queue-reset.patch queue-4.4/batman-adv-set-.owner-to-this_module.patch queue-4.4/batman-adv-mcast-fix-duplicate-mcast-packets-from-bla-backbone-to-mesh.patch queue-4.4/batman-adv-fix-multicast-tt-issues-with-bogus-roam-flags.patch queue-4.4/batman-adv-mcast-fix-duplicate-mcast-packets-in-bla-backbone-from-lan.patch queue-4.4/batman-adv-reserve-needed_-room-for-fragments.patch queue-4.4/net-batman-adv-fix-error-handling.patch queue-4.4/batman-adv-keep-fragments-equally-sized.patch queue-4.4/batman-adv-avoid-warn_on-timing-related-checks.patch queue-4.4/batman-adv-prevent-duplicated-softif_vlan-entry.patch queue-4.4/batman-adv-don-t-always-reallocate-the-fragmentation-skb-head.patch queue-4.4/batman-adv-mcast-fix-duplicate-mcast-packets-in-bla-backbone-from-mesh.patch