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 1E4B21DED58; Wed, 6 Nov 2024 12:25:42 +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=1730895942; cv=none; b=H5WEjTsytJVr5EOqK5MeQCMOw8+y5S8qieEJmjWXy/A324uwHEJA2ueeyiUp5FPGJ1fhq+GsQLqqItVAvNqu1s9lcwR1jId787dHooy1kox8zJjUI0gnxqSNum2MsrByNWBLfsQtIgsFPktKM8udx5Srs1ALBpLxPye0pSA5XEI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730895942; c=relaxed/simple; bh=a8vzpWF8BOFgBft0N6/wyGz/fUgfXS8wdbytspuLy8g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rCy2/jWT8u/McTq+527AnmL6DZQK6iV8KXf0R1lsvZayyUfuY/WtCdlc1roxJABphM096ngAuqwUx8+tSV37nMbofbD+Let1T13nFgd5NsR67JZdD4zxVliwD46s8V+YjBIRy4YLZieGICotn+aFJkX7fSJMfHhsGLsb2dECi0Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BK9HxQfz; 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="BK9HxQfz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98BA6C4CECD; Wed, 6 Nov 2024 12:25:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730895942; bh=a8vzpWF8BOFgBft0N6/wyGz/fUgfXS8wdbytspuLy8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BK9HxQfzRk/3um9dNeJ1sp4v4c5ADJuE+mkwvcXK52HhWcqfy63oakLL1uLmEHSJi eVSk2WubUnSzZnQl/7Ckctoffv/9L/7hk1kZYBI7XEUXs1Pdj2hAQzMomb6aMj6xPy mulNvZ3OwN0nZ5W+GmKBp+WjqbaYc1TO0DvZvhM4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Ido Schimmel , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.11 035/245] ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find() Date: Wed, 6 Nov 2024 13:01:28 +0100 Message-ID: <20241106120320.090025493@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120319.234238499@linuxfoundation.org> References: <20241106120319.234238499@linuxfoundation.org> User-Agent: quilt/0.67 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 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ido Schimmel [ Upstream commit 90e0569dd3d32f4f4d2ca691d3fa5a8a14a13c12 ] The per-netns IP tunnel hash table is protected by the RTNL mutex and ip_tunnel_find() is only called from the control path where the mutex is taken. Add a lockdep expression to hlist_for_each_entry_rcu() in ip_tunnel_find() in order to validate that the mutex is held and to silence the suspicious RCU usage warning [1]. [1] WARNING: suspicious RCU usage 6.12.0-rc3-custom-gd95d9a31aceb #139 Not tainted ----------------------------- net/ipv4/ip_tunnel.c:221 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by ip/362: #0: ffffffff86fc7cb0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x377/0xf60 stack backtrace: CPU: 12 UID: 0 PID: 362 Comm: ip Not tainted 6.12.0-rc3-custom-gd95d9a31aceb #139 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack_lvl+0xba/0x110 lockdep_rcu_suspicious.cold+0x4f/0xd6 ip_tunnel_find+0x435/0x4d0 ip_tunnel_newlink+0x517/0x7a0 ipgre_newlink+0x14c/0x170 __rtnl_newlink+0x1173/0x19c0 rtnl_newlink+0x6c/0xa0 rtnetlink_rcv_msg+0x3cc/0xf60 netlink_rcv_skb+0x171/0x450 netlink_unicast+0x539/0x7f0 netlink_sendmsg+0x8c1/0xd80 ____sys_sendmsg+0x8f9/0xc20 ___sys_sendmsg+0x197/0x1e0 __sys_sendmsg+0x122/0x1f0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Suggested-by: Eric Dumazet Signed-off-by: Ido Schimmel Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20241023123009.749764-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/ip_tunnel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 5cffad42fe8ca..49937878d5e8a 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -217,7 +217,7 @@ static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn, ip_tunnel_flags_copy(flags, parms->i_flags); - hlist_for_each_entry_rcu(t, head, hash_node) { + hlist_for_each_entry_rcu(t, head, hash_node, lockdep_rtnl_is_held()) { if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr && link == READ_ONCE(t->parms.link) && -- 2.43.0