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From:   Zheyu Ma <zheyuma97@gmail.com>
To:     gregkh@linuxfoundation.org, jirislaby@kernel.org, fseidel@suse.de
Cc:     linux-kernel@vger.kernel.org, Zheyu Ma <zheyuma97@gmail.com>
Subject: [PATCH] tty: nozomi: Return an error when failing to create the sysfs
Date:   Thu,  9 Jun 2022 16:31:33 +0800
Message-Id: <20220609083133.4120738-1-zheyuma97@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The driver does not handle the error of the creation of sysfs, resulting
in duplicate file names being created.

The following log can reveal it:

[   52.907211] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:05.0/card_type'
[   52.907224] Call Trace:
[   52.907269]  sysfs_add_file_mode_ns+0x23f/0x2b0
[   52.907281]  sysfs_create_file_ns+0xe9/0x170
[   52.907321]  nozomi_card_init+0x97f/0x12c0 [nozomi]

Fix this bug by returning an error when failing to create the sysfs.

Fixes: 20fd1e3bea55 ("nozomi driver")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
 drivers/tty/nozomi.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index 0454c78deee6..d0ad1b9898f5 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -1282,14 +1282,26 @@ static ssize_t open_ttys_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(open_ttys);
 
-static void make_sysfs_files(struct nozomi *dc)
+static int make_sysfs_files(struct nozomi *dc)
 {
-	if (device_create_file(&dc->pdev->dev, &dev_attr_card_type))
+	int err;
+
+	err = device_create_file(&dc->pdev->dev, &dev_attr_card_type);
+	if (err) {
 		dev_err(&dc->pdev->dev,
 			"Could not create sysfs file for card_type\n");
-	if (device_create_file(&dc->pdev->dev, &dev_attr_open_ttys))
+		return err;
+	}
+
+	err = device_create_file(&dc->pdev->dev, &dev_attr_open_ttys);
+	if (err) {
+		device_remove_file(&dc->pdev->dev, &dev_attr_card_type);
 		dev_err(&dc->pdev->dev,
 			"Could not create sysfs file for open_ttys\n");
+		return err;
+	}
+
+	return 0;
 }
 
 static void remove_sysfs_files(struct nozomi *dc)
@@ -1383,7 +1395,9 @@ static int nozomi_card_init(struct pci_dev *pdev,
 
 	DBG1("base_addr: %p", dc->base_addr);
 
-	make_sysfs_files(dc);
+	ret = make_sysfs_files(dc);
+	if (ret)
+		goto err_free_irq;
 
 	dc->index_start = ndev_idx * MAX_PORT;
 	ndevs[ndev_idx] = dc;
@@ -1420,6 +1434,8 @@ static int nozomi_card_init(struct pci_dev *pdev,
 		tty_unregister_device(ntty_driver, dc->index_start + i);
 		tty_port_destroy(&dc->port[i].port);
 	}
+	remove_sysfs_files(dc);
+err_free_irq:
 	free_irq(pdev->irq, dc);
 err_free_all_kfifo:
 	i = MAX_PORT;
-- 
2.25.1