From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8923B4EB853; Wed, 23 Sep 2026 14:09:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790172598; cv=none; b=Ag6CCnJj/ZUrE6dwUDoWTCZgIBCCStZjsho19BgBb0Y5LEvnyUiZjUZbFfAbWjdFi0wroReCxRoCaSCvKbLlmNZwIfjK3hF/Gc6xRwDuxviCi9pm8shnVJKe4wiCGVGKESrCE0vh5IXh1AOYRYuwPbLs0SourqqpHVcwCjlTiSc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790172598; c=relaxed/simple; bh=p0iwWaAXnnPOXhucXC+hZkZBAoiWJ267b0iAXxyWxoQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N57ecz/6+nS3+QAIna3Cxjz/21E9S3acCHubjb/Rvvswv5l4r+rp2klPdzUQbm1sz63fqk9zI/iU0tJ6Iqla2/9IAke2jccWim2GyMOyAhMVqNz12TJ2Os/tTIIH53rRLXyUW8VFuy+t56M0rRURlkqzYHJYEg+rMsqZy2BpBgw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MFl62URV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MFl62URV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 847631F000FF; Wed, 23 Sep 2026 14:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790172597; bh=p0dbSgMaL4IeG5/VHq8Ffc7SGRbOafkv8Sny8knrbP8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MFl62URV3K07AFMBttYHeeko42/3cD+AFDQOM37S0ll1oyTyt+rNfvqwbbkJRtAKm dYytrNMjrtUc1XGNF8vrw++QeG+ocNxuTmj5Gm0JYY7vsuMDnbcz//VqNq+3yx5iFU JzregvGjYHlSbglUuPFA+8kOOy/IGCNBk6wDFcvM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+c0e99a1aa85a286d7a3b@syzkaller.appspotmail.com, Aleksandr Nogikh , Steffen Klassert , Sasha Levin Subject: [PATCH 7.2 006/438] xfrm: add missing RCU read lock in xfrm_send_migrate_state() Date: Wed, 23 Sep 2026 16:00:27 +0200 Message-ID: <20260923140644.929931923@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140644.756254324@linuxfoundation.org> References: <20260923140644.756254324@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aleksandr Nogikh [ Upstream commit 42d100f5232f39b8ea7b00a7c2482325c7f032a4 ] xfrm_nlmsg_multicast() requires the RCU read lock to be held because it safely dereferences the net->xfrm.nlsk pointer using rcu_dereference(). When it is called from xfrm_send_migrate_state(), the RCU read lock is not held, which triggers a suspicious RCU usage warning: WARNING: suspicious RCU usage net/xfrm/xfrm_user.c:1630 suspicious rcu_dereference_check() usage! Call Trace: lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876 xfrm_nlmsg_multicast+0x1d8/0x1f0 net/xfrm/xfrm_user.c:1630 xfrm_send_migrate_state+0x870/0xae0 net/xfrm/xfrm_user.c:3340 xfrm_do_migrate_state+0x1749/0x1e90 net/xfrm/xfrm_user.c:3507 xfrm_user_rcv_msg+0x7a8/0xf30 net/xfrm/xfrm_user.c:3907 Fix this by wrapping the xfrm_nlmsg_multicast() call in xfrm_send_migrate_state() with rcu_read_lock() and rcu_read_unlock(). Fixes: a9d155ea9b44 ("xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migration") Assisted-by: Gemini:gemini-3.5-flash Gemini:gemini-3.1-pro-preview syzbot Reported-by: syzbot+c0e99a1aa85a286d7a3b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c0e99a1aa85a286d7a3b Link: https://syzkaller.appspot.com/ai_job?id=8977f559-3a7e-4bb5-b4d6-1196956260b6 Signed-off-by: Aleksandr Nogikh Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_user.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 6266a92cf3020..980dbeb5a57de 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -3337,7 +3337,11 @@ static int xfrm_send_migrate_state(struct net *net, return err; } - return xfrm_nlmsg_multicast(net, skb, 0, XFRMNLGRP_MIGRATE); + rcu_read_lock(); + err = xfrm_nlmsg_multicast(net, skb, 0, XFRMNLGRP_MIGRATE); + rcu_read_unlock(); + + return err; } static int xfrm_do_migrate_state(struct sk_buff *skb, struct nlmsghdr *nlh, -- 2.53.0