From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A071B282F1C; Mon, 13 Apr 2026 16:04:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776096297; cv=none; b=TOgcs9ZR+yw4D9AA9SDdXZj/Ltt2kT0Dysp1KBClPjeYlmkGLNIdU4Ssdw2kdBw8d8qPVpr9KVnPNMHfIL+rOOGA6gZFu/fC49rDvTrBv1fH2L7MW/a61uCve/8EyG51/lljUHyob30Pd15FgS1YJG5ZT0YfrvHF1s/8XYb1hF8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776096297; c=relaxed/simple; bh=V37Q5DMlOo9avUG9a92mTh4Ux3+dcSgHvk+UgfG1C7Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=n4vMvkhu+gMXohtQ3cAQY+mXV7uhPng3lhYFOCZaCvYGrMvK3zMxiv2199Ly3ssSc6vnaXBYoUpWNUbnnIQhqrnOwD88InjOyLUmKjtzTRnc25b/yUAStF4FBMIdoQj9wvj29FSkletbCdCGFG1GhEp0fGKQQbmblfoiwvqDN3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qY46S/6G; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qY46S/6G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37DF0C2BCB0; Mon, 13 Apr 2026 16:04:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776096297; bh=V37Q5DMlOo9avUG9a92mTh4Ux3+dcSgHvk+UgfG1C7Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qY46S/6GRcCTbs9FCb7v6EaFBQg48VCjWHhgqaMLWOaolYOjGNIeqrt8+4EYXmjxS KPb/BnwzA5OhzOF3Vx5q4vffiRxm/twJlJIMK90Apr6FfKReKFMPFFEDbVZp3V+7XJ aKQLtHPizM3/grr4zr+TXHGP9WgPDuJ967mJX2cs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yifan Wu , Juefei Pu , Yuan Tan , Xin Liu , Haoze Xie , Ao Zhou , Sven Eckelmann , Simon Wunderlich Subject: [PATCH 6.19 44/86] batman-adv: hold claim backbone gateways by reference Date: Mon, 13 Apr 2026 17:59:51 +0200 Message-ID: <20260413155733.210789040@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155731.568515178@linuxfoundation.org> References: <20260413155731.568515178@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 6.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Haoze Xie commit 82d8701b2c930d0e96b0dbc9115a218d791cb0d2 upstream. batadv_bla_add_claim() can replace claim->backbone_gw and drop the old gateway's last reference while readers still follow the pointer. The netlink claim dump path dereferences claim->backbone_gw->orig and takes claim->backbone_gw->crc_lock without pinning the underlying backbone gateway. batadv_bla_check_claim() still has the same naked pointer access pattern. Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate on a stable gateway reference until the read-side work is complete. This keeps the dump and claim-check paths aligned with the lifetime rules introduced for the other BLA claim readers. Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code") Fixes: 04f3f5bf1883 ("batman-adv: add B.A.T.M.A.N. Dump BLA claims via netlink") Cc: stable@vger.kernel.org Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Haoze Xie Signed-off-by: Ao Zhou Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/bridge_loop_avoidance.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -2130,6 +2130,7 @@ batadv_bla_claim_dump_entry(struct sk_bu struct batadv_bla_claim *claim) { const u8 *primary_addr = primary_if->net_dev->dev_addr; + struct batadv_bla_backbone_gw *backbone_gw; u16 backbone_crc; bool is_own; void *hdr; @@ -2145,32 +2146,35 @@ batadv_bla_claim_dump_entry(struct sk_bu genl_dump_check_consistent(cb, hdr); - is_own = batadv_compare_eth(claim->backbone_gw->orig, - primary_addr); + backbone_gw = batadv_bla_claim_get_backbone_gw(claim); + + is_own = batadv_compare_eth(backbone_gw->orig, primary_addr); - spin_lock_bh(&claim->backbone_gw->crc_lock); - backbone_crc = claim->backbone_gw->crc; - spin_unlock_bh(&claim->backbone_gw->crc_lock); + spin_lock_bh(&backbone_gw->crc_lock); + backbone_crc = backbone_gw->crc; + spin_unlock_bh(&backbone_gw->crc_lock); if (is_own) if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) { genlmsg_cancel(msg, hdr); - goto out; + goto put_backbone_gw; } if (nla_put(msg, BATADV_ATTR_BLA_ADDRESS, ETH_ALEN, claim->addr) || nla_put_u16(msg, BATADV_ATTR_BLA_VID, claim->vid) || nla_put(msg, BATADV_ATTR_BLA_BACKBONE, ETH_ALEN, - claim->backbone_gw->orig) || + backbone_gw->orig) || nla_put_u16(msg, BATADV_ATTR_BLA_CRC, backbone_crc)) { genlmsg_cancel(msg, hdr); - goto out; + goto put_backbone_gw; } genlmsg_end(msg, hdr); ret = 0; +put_backbone_gw: + batadv_backbone_gw_put(backbone_gw); out: return ret; } @@ -2448,6 +2452,7 @@ out: bool batadv_bla_check_claim(struct batadv_priv *bat_priv, u8 *addr, unsigned short vid) { + struct batadv_bla_backbone_gw *backbone_gw; struct batadv_bla_claim search_claim; struct batadv_bla_claim *claim = NULL; struct batadv_hard_iface *primary_if = NULL; @@ -2470,9 +2475,13 @@ bool batadv_bla_check_claim(struct batad * return false. */ if (claim) { - if (!batadv_compare_eth(claim->backbone_gw->orig, + backbone_gw = batadv_bla_claim_get_backbone_gw(claim); + + if (!batadv_compare_eth(backbone_gw->orig, primary_if->net_dev->dev_addr)) ret = false; + + batadv_backbone_gw_put(backbone_gw); batadv_claim_put(claim); }