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 8852B352955 for ; Thu, 18 Dec 2025 15:37:49 +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=1766072269; cv=none; b=cKNTCouRzkovIyIriu0PZ5XySFfXOKJ2MLWjnv9ldOZbIceMBDIrJ9czkz5pRkW3s2Fiii7VNfDBFm7u+FLqnheoml94l2ceoHhsOXNbrduZpPPMG5ot90DDQA2kD8eK6amXob7v7tb0YcMddgCeHGiVcRS2a7Hy2VT/PfesuGI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766072269; c=relaxed/simple; bh=R3fXwdr0A1Zs+QfZJ36SAZALrBl+SyZmZZHeXt6CsVE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Pe6CyElIFADZSSIdfuu/ym6iuJkIchl8dWDnO4hJpB3reNq3qB5nmZktiC9PFMJSxJi6rmGwil8Cd1YDS5lomUtYJ8ssXWPNSwcSF2x/vHX0ceAe6wIneS1QCebl+3sNrVFCEpgP+EemJz9eYml2d2lmrEGuoF7M/z8PzgKSLTs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=szOBLTTl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="szOBLTTl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9868CC4CEFB; Thu, 18 Dec 2025 15:37:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766072269; bh=R3fXwdr0A1Zs+QfZJ36SAZALrBl+SyZmZZHeXt6CsVE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=szOBLTTlSqPO/UqOyGyJXV1HmeCdcxI68uN6BEbQmwRsShQxLKleolGmXGCg12CST MQ25cDCk1cwA5ZN+8vnozzbT9bmnqJEJwG0myn7eLcds2oIRZ7E1lH4sI4WhqGtcPY GKFMd3gE8rHd3Cq4BjlFd5OHXKsw/bapzB5/qVPP6aplxFVjYxBsUWFq1+xcpUlInY NOCeeMusUQvXhWbf090LIuKfGJu5DuQWdNp6Ffv3PO7IUUJcoeJ3nQ2XnbU4kmRmFR F5nM/PHHB2MD8Asa1n6AvwHXgVTQ47VyeozOY5TdWYUQIc/2slT4XQjB9BT26yAOxM iNwrZlMhDrDPg== From: Sasha Levin To: stable@vger.kernel.org Cc: Hangbin Liu , Paolo Abeni , Simon Horman , Sasha Levin Subject: [PATCH 6.12.y] hsr: hold rcu and dev lock for hsr_get_port_ndev Date: Thu, 18 Dec 2025 10:37:36 -0500 Message-ID: <20251218153736.3435271-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025121829-aloof-cresting-f057@gregkh> References: <2025121829-aloof-cresting-f057@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Hangbin Liu [ Upstream commit 847748fc66d08a89135a74e29362a66ba4e3ab15 ] hsr_get_port_ndev calls hsr_for_each_port, which need to hold rcu lock. On the other hand, before return the port device, we need to hold the device reference to avoid UaF in the caller function. Suggested-by: Paolo Abeni Fixes: 9c10dd8eed74 ("net: hsr: Create and export hsr_get_port_ndev()") Signed-off-by: Hangbin Liu Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250905091533.377443-4-liuhangbin@gmail.com Signed-off-by: Paolo Abeni [ Drop multicast filtering changes ] Signed-off-by: Sasha Levin --- net/hsr/hsr_device.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c index 386aba50930a3..acbd77ce6afce 100644 --- a/net/hsr/hsr_device.c +++ b/net/hsr/hsr_device.c @@ -682,9 +682,14 @@ struct net_device *hsr_get_port_ndev(struct net_device *ndev, struct hsr_priv *hsr = netdev_priv(ndev); struct hsr_port *port; + rcu_read_lock(); hsr_for_each_port(hsr, port) - if (port->type == pt) + if (port->type == pt) { + dev_hold(port->dev); + rcu_read_unlock(); return port->dev; + } + rcu_read_unlock(); return NULL; } EXPORT_SYMBOL(hsr_get_port_ndev); -- 2.51.0