From: Sven Eckelmann sven@narfation.org

mainline inclusion from mainline-v5.13-rc7 commit 9f460ae31c4435fd022c443a6029352217a16ac1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4GZ CVE: CVE-2021-47252

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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@i-love.sakura.ne.jp Reported-by: syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com Fixes: ef0a937f7a14 ("batman-adv: consider outgoing interface in OGM sending") Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de Signed-off-by: He Yujie coka.heyujie@huawei.com --- net/batman-adv/bat_iv_ogm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index f5941837c3ad..cf86438edb2e 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -594,8 +594,10 @@ static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet) if (WARN_ON(!forw_packet->if_outgoing)) return;

- 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__); return; + }

if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE) return;