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 464F21DF254; Tue, 8 Oct 2024 13:27:21 +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=1728394041; cv=none; b=LMUkPn5p9YE/jFwSlj9oE/ffOjz3e6KZrkSeM61jbxqO6OtCnvXk6jTg4URFij0Csy7VGoexGP8JXZRKHgU1lsh4DpzPuh+wOude0b0stSFn9ck/0wACNTrIoz4bLqWMtpUudFRv0lKyEXDjV0Gt86976pUcnfBDvgComFQaHXo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728394041; c=relaxed/simple; bh=znrQcowjjeI7d2ohEiAqz/e+zbWYeOqg/dWojRLJysM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T270vcSUqywkJtFtFFc46OY58rdYnOypulGQEwY1zbKEOJxzymqQ/w+NJfvvteO81vYISoqZYwTf/NAdMvjkcYEazJKSjBmlvEy748N1Kr2hmmzibAUr2+f8g4hNXC2hgbMhqU47hyXNlEnWsnZzSAWViU19G2LIYWCUdzU9pf4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VqJwB3uz; 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="VqJwB3uz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A836DC4CEC7; Tue, 8 Oct 2024 13:27:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728394041; bh=znrQcowjjeI7d2ohEiAqz/e+zbWYeOqg/dWojRLJysM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VqJwB3uzLDDqoJdvQDCpVzSdv69/jBO6lCq2IP29zOpiZNSVe0eOHaIigUGVK2T9l khLyhUy4lbjUivY6Nc2+qLabwCNSHj76qfR5F2MVdD+GX7hwdDloTGa0XEz04MKFXu 1CNfopP4cqk9X2YsgwalB/9QW9C+xR1xMkRLd3Ec= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ben Greear , Willem de Bruijn , Ido Schimmel , David Ahern , Jakub Kicinski Subject: [PATCH 6.6 298/386] vrf: revert "vrf: Remove unnecessary RCU-bh critical section" Date: Tue, 8 Oct 2024 14:09:03 +0200 Message-ID: <20241008115641.113661666@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115629.309157387@linuxfoundation.org> References: <20241008115629.309157387@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Willem de Bruijn commit b04c4d9eb4f25b950b33218e33b04c94e7445e51 upstream. This reverts commit 504fc6f4f7f681d2a03aa5f68aad549d90eab853. dev_queue_xmit_nit is expected to be called with BH disabled. __dev_queue_xmit has the following: /* Disable soft irqs for various locks below. Also * stops preemption for RCU. */ rcu_read_lock_bh(); VRF must follow this invariant. The referenced commit removed this protection. Which triggered a lockdep warning: ================================ WARNING: inconsistent lock state 6.11.0 #1 Tainted: G W -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. btserver/134819 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff8882da30c118 (rlock-AF_PACKET){+.?.}-{2:2}, at: tpacket_rcv+0x863/0x3b30 {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x19a/0x4f0 _raw_spin_lock+0x27/0x40 packet_rcv+0xa33/0x1320 __netif_receive_skb_core.constprop.0+0xcb0/0x3a90 __netif_receive_skb_list_core+0x2c9/0x890 netif_receive_skb_list_internal+0x610/0xcc0 [...] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rlock-AF_PACKET); lock(rlock-AF_PACKET); *** DEADLOCK *** Call Trace: dump_stack_lvl+0x73/0xa0 mark_lock+0x102e/0x16b0 __lock_acquire+0x9ae/0x6170 lock_acquire+0x19a/0x4f0 _raw_spin_lock+0x27/0x40 tpacket_rcv+0x863/0x3b30 dev_queue_xmit_nit+0x709/0xa40 vrf_finish_direct+0x26e/0x340 [vrf] vrf_l3_out+0x5f4/0xe80 [vrf] __ip_local_out+0x51e/0x7a0 [...] Fixes: 504fc6f4f7f6 ("vrf: Remove unnecessary RCU-bh critical section") Link: https://lore.kernel.org/netdev/20240925185216.1990381-1-greearb@candelatech.com/ Reported-by: Ben Greear Signed-off-by: Willem de Bruijn Cc: stable@vger.kernel.org Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/20240929061839.1175300-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/vrf.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/vrf.c +++ b/drivers/net/vrf.c @@ -628,7 +628,9 @@ static void vrf_finish_direct(struct sk_ eth_zero_addr(eth->h_dest); eth->h_proto = skb->protocol; + rcu_read_lock_bh(); dev_queue_xmit_nit(skb, vrf_dev); + rcu_read_unlock_bh(); skb_pull(skb, ETH_HLEN); }