CVE-2022-24958 (published 2022-02-11T06:15Z)

drivers/usb/gadget/legacy/inode.c in the Linux kernel through 5.16.8 mishandles dev->buf release.

Severity: MEDIUM
CVSS v2 base score: 4.6 (AV:L/AC:L/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 7.8, HIGH (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-763
cwe_name: Release of Invalid Pointer or Reference
description: The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.
extended_description: 
            This weakness can take several forms, such as:
               
                  The memory was allocated, explicitly or implicitly, via one memory management method and deallocated using a different, non-compatible function (CWE-762).
                  The function calls or memory management routines chosen are appropriate, however they are used incorrectly, such as in CWE-761.
               
         
         

Fix information:
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Hangyu Hua
author_date: 2022-01-01 01:21:38+08:00
msg: 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@rowland.harvard.edu>
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lore.kernel.org/r/20211231172138.7993-3-hbh25y@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: inode.c
change_type: ModificationType.MODIFY
diff: @@ -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);

programming_language: C
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Hangyu Hua
author_date: 2022-01-01 01:21:37+08:00
msg: usb: gadget: don't release an existing dev->buf

dev->buf does not need to be released if it already exists before
executing dev_config.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lore.kernel.org/r/20211231172138.7993-2-hbh25y@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: inode.c
change_type: ModificationType.MODIFY
diff: @@ -1826,8 +1826,9 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	spin_lock_irq (&dev->lock);
 	value = -EINVAL;
 	if (dev->buf) {
+		spin_unlock_irq(&dev->lock);
 		kfree(kbuf);
-		goto fail;
+		return value;
 	}
 	dev->buf = kbuf;
 

programming_language: C