linux-kernel - [PATCH 4.14 2/2] usb: gadget: clear related members when goto fail

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Tue,  1 Mar 2022 10:26:08 +0800
From:   Hangyu Hua <hbh25y@...il.com>
To:     gregkh@...uxfoundation.org
Cc:     stable@...r.kernel.org, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org, ben@...adent.org.uk,
        balbi@...nel.org, axboe@...nel.dk, mingo@...nel.org,
        jj251510319013@...il.com, zsm@...omium.org,
        stern@...land.harvard.edu, Hangyu Hua <hbh25y@...il.com>
Subject: [PATCH 4.14 2/2] usb: gadget: clear related members when goto fail

dev->config and dev->hs_config and dev->dev need to be cleaned if
dev_config fails to avoid UAF.

Acked-by: Alan Stern <stern@...land.harvard.edu>
Signed-off-by: Hangyu Hua <hbh25y@...il.com>
Link: https://lore.kernel.org/r/20211231172138.7993-2-hbh25y@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: stable@...r.kernel.org #4.4+
---
 drivers/usb/gadget/legacy/inode.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index eaad03c0252f..25c8809e0a38 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -1875,8 +1875,8 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 
 	value = usb_gadget_probe_driver(&gadgetfs_driver);
 	if (value != 0) {
-		kfree (dev->buf);
-		dev->buf = NULL;
+		spin_lock_irq(&dev->lock);
+		goto fail;
 	} else {
 		/* at this point "good" hardware has for the first time
 		 * let the USB the host see us.  alternatively, if users
@@ -1893,6 +1893,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	return value;
 
 fail:
+	dev->config = NULL;
+	dev->hs_config = NULL;
+	dev->dev = NULL;
 	spin_unlock_irq (&dev->lock);
 	pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
 	kfree (dev->buf);
-- 
2.25.1