CVE-2021-47173 misc/uss720: fix memory leak in uss720_probe

Medium 5.5 Published Updated

A memory leak in the uss720 driver allows attackers to exhaust kernel memory, potentially causing a 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-2021-47173?

CVE-2021-47173 is a medium-severity memory corruption vulnerability in Linux kernel, published on 25 Mar 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:

misc/uss720: fix memory leak in uss720_probe

uss720_probe forgets to decrease the refcount of usbdev in uss720_probe. Fix this by decreasing the refcount of usbdev by usb_put_dev.

BUG: memory leak unreferenced object 0xffff888101113800 (size 2048): comm "kworker/0:1", pid 7, jiffies 4294956777 (age 28.870s) hex dump (first 32 bytes): ff ff ff ff 31 00 00 00 00 00 00 00 00 00 00 00 ....1........... 00 00 00 00 00 00 00 00 00 00 00 00 03 00 00 00 ................ backtrace: [<ffffffff82b8e822>] kmalloc include/linux/slab.h:554 [inline] [<ffffffff82b8e822>] kzalloc include/linux/slab.h:684 [inline] [<ffffffff82b8e822>] usb_alloc_dev+0x32/0x450 drivers/usb/core/usb.c:582 [<ffffffff82b98441>] hub_port_connect drivers/usb/core/hub.c:5129 [inline] [<ffffffff82b98441>] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] [<ffffffff82b98441>] port_event drivers/usb/core/hub.c:5509 [inline] [<ffffffff82b98441>] hub_event+0x1171/0x20c0 drivers/usb/core/hub.c:5591 [<ffffffff81259229>] process_one_work+0x2c9/0x600 kernel/workqueue.c:2275 [<ffffffff81259b19>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2421 [<ffffffff81261228>] kthread+0x178/0x1b0 kernel/kthread.c:292 [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Weakness: CWE-401

Which versions are affected by CVE-2021-47173?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47173?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-47173 being exploited?

There is no known exploitation of CVE-2021-47173 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as DEBIAN-CVE-2021-47173, GHSA-8rjr-8h65-297v, UBUNTU-CVE-2021-47173.

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