CVE-2021-47528 usb: cdnsp: Fix a NULL pointer dereference in cdnsp_endpoint_init()
A NULL pointer dereference in the Linux kernel's cdnsp USB gadget driver can cause a system crash, requiring a patched kernel to prevent denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-47528?
CVE-2021-47528 is a medium-severity vulnerability in Linux kernel, published on 24 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
usb: cdnsp: Fix a NULL pointer dereference in cdnsp_endpoint_init()
In cdnsp_endpoint_init(), cdnsp_ring_alloc() is assigned to pep->ring and there is a dereference of it in cdnsp_endpoint_init(), which could lead to a NULL pointer dereference on failure of cdnsp_ring_alloc().
Fix this bug by adding a check of pep->ring.
This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs.
Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug.
Builds with CONFIG_USB_CDNSP_GADGET=y show no new warnings, and our static analyzer no longer warns about this code.
Weakness: CWE-476
Which versions are affected by CVE-2021-47528?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47528?
Apply the vendor's patch.
Is CVE-2021-47528 being exploited?
There is no known exploitation of CVE-2021-47528 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47528, UBUNTU-CVE-2021-47528.