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 1A70F6FBB for ; Tue, 10 Jan 2023 18:26:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74D91C433EF; Tue, 10 Jan 2023 18:26:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673375181; bh=AIqqYvq4AIDF5nBYlo0SKI2ihqFbvKDY7cGRkNiegtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Owsh/gRGBBqs+qssdz5NlH91b7ehU+HpIZm5DE8ODRdQVBPLRa5Jv8yQyGo5nFrg6 F+Y8915lKJRZwg8+V8PEcCRfg+f5Ze8Kgx2WpKIVxcVBNUa/yNuxtS5Cka8RbpcUPL gfkkMzXhx6lNcaEOWdWmDTTxeTKUJ7uE1yKQISYA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sowjanya Komatineni , Luca Ceresoli , Hans Verkuil Subject: [PATCH 5.15 106/290] staging: media: tegra-video: fix device_node use after free Date: Tue, 10 Jan 2023 19:03:18 +0100 Message-Id: <20230110180035.423844388@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230110180031.620810905@linuxfoundation.org> References: <20230110180031.620810905@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Luca Ceresoli commit c4d344163c3a7f90712525f931a6c016bbb35e18 upstream. At probe time this code path is followed: * tegra_csi_init * tegra_csi_channels_alloc * for_each_child_of_node(node, channel) -- iterates over channels * automatically gets 'channel' * tegra_csi_channel_alloc() * saves into chan->of_node a pointer to the channel OF node * automatically gets and puts 'channel' * now the node saved in chan->of_node has refcount 0, can disappear * tegra_csi_channels_init * iterates over channels * tegra_csi_channel_init -- uses chan->of_node After that, chan->of_node keeps storing the node until the device is removed. of_node_get() the node and of_node_put() it during teardown to avoid any risk. Fixes: 1ebaeb09830f ("media: tegra-video: Add support for external sensor capture") Cc: stable@vger.kernel.org Cc: Sowjanya Komatineni Signed-off-by: Luca Ceresoli Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/staging/media/tegra-video/csi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/staging/media/tegra-video/csi.c +++ b/drivers/staging/media/tegra-video/csi.c @@ -433,7 +433,7 @@ static int tegra_csi_channel_alloc(struc for (i = 0; i < chan->numgangports; i++) chan->csi_port_nums[i] = port_num + i * CSI_PORTS_PER_BRICK; - chan->of_node = node; + chan->of_node = of_node_get(node); chan->numpads = num_pads; if (num_pads & 0x2) { chan->pads[0].flags = MEDIA_PAD_FL_SINK; @@ -641,6 +641,7 @@ static void tegra_csi_channels_cleanup(s media_entity_cleanup(&subdev->entity); } + of_node_put(chan->of_node); list_del(&chan->list); kfree(chan); }