Vulnerability CVE-2021-47170
Published: 2024-03-25

Description:
In the Linux kernel, the following vulnerability has been resolved:

USB: usbfs: Don't WARN about excessively large memory allocations

Syzbot found that the kernel generates a WARNing if the user tries to
submit a bulk transfer through usbfs with a buffer that is way too
large. This isn't a bug in the kernel; it's merely an invalid request
from the user and the usbfs code does handle it correctly.

In theory the same thing can happen with async transfers, or with the
packet descriptor table for isochronous transfers.

To prevent the MM subsystem from complaining about these bad
allocation requests, add the __GFP_NOWARN flag to the kmalloc calls
for these buffers.

 References:
https://git.kernel.org/stable/c/2ab21d6e1411999b5fb43434f421f00bf50002eb
https://git.kernel.org/stable/c/2c835fede13e03f2743a333e4370b5ed2db91e83
https://git.kernel.org/stable/c/8d83f109e920d2776991fa142bb904d985dca2ed
https://git.kernel.org/stable/c/9f7cb3f01a10d9064cf13b3d26fb7e7a5827d098
https://git.kernel.org/stable/c/4f2629ea67e7225c3fd292c7fe4f5b3c9d6392de
Copyright 2026, cxsecurity.com

 

Back to Top