This is a note to let you know that I've just added the patch titled batman-adv: Consider fragmentation for needed_headroom to the 4.9-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-consider-fragmentation-for-needed_headroom.patch and it can be found in the queue-4.9 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 01:37:10 PM CET 2021 From: Sven Eckelmann <sven@xxxxxxxxxxxxx> Date: Sat, 20 Nov 2021 13:39:56 +0100 Subject: batman-adv: Consider fragmentation for needed_headroom To: stable@xxxxxxxxxxxxxxx Cc: b.a.t.m.a.n@xxxxxxxxxxxxxxxxxxx, "Sven Eckelmann" <sven@xxxxxxxxxxxxx>, "Linus Lüssing" <linus.luessing@xxxxxxxxx>, "Simon Wunderlich" <sw@xxxxxxxxxxxxxxxxxx> Message-ID: <20211120123958.260826-6-sven@xxxxxxxxxxxxx> From: Sven Eckelmann <sven@xxxxxxxxxxxxx> commit 4ca23e2c2074465bff55ea14221175fecdf63c5f upstream. If a batman-adv packets has to be fragmented, then the original batman-adv packet header is not stripped away. Instead, only a new header is added in front of the packet after it was split. This size must be considered to avoid cost intensive reallocations during the transmission through the various device layers. Fixes: 7bca68c7844b ("batman-adv: Add lower layer needed_(head|tail)room to own ones") Reported-by: Linus Lüssing <linus.luessing@xxxxxxxxx> Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx> Signed-off-by: Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/batman-adv/hard-interface.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -359,6 +359,9 @@ static void batadv_hardif_recalc_extra_s needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN); needed_headroom += batadv_max_header_len(); + /* fragmentation headers don't strip the unicast/... header */ + needed_headroom += sizeof(struct batadv_frag_packet); + soft_iface->needed_headroom = needed_headroom; soft_iface->needed_tailroom = lower_tailroom; } Patches currently in stable-queue which might be from sven@xxxxxxxxxxxxx are queue-4.9/batman-adv-consider-fragmentation-for-needed_headroom.patch queue-4.9/ath9k-fix-potential-interrupt-storm-on-queue-reset.patch queue-4.9/batman-adv-mcast-fix-duplicate-mcast-packets-from-bla-backbone-to-mesh.patch queue-4.9/ath10k-fix-max-antenna-gain-unit.patch queue-4.9/batman-adv-mcast-fix-duplicate-mcast-packets-in-bla-backbone-from-lan.patch queue-4.9/batman-adv-reserve-needed_-room-for-fragments.patch queue-4.9/batman-adv-fix-own-ogm-check-in-aggregated-ogms.patch queue-4.9/batman-adv-keep-fragments-equally-sized.patch queue-4.9/batman-adv-don-t-always-reallocate-the-fragmentation-skb-head.patch