usb: cdc-acm: BUG kmalloc-128 Poison overwritten

Oliver Neukum oneukum at
Thu Feb 25 04:57:50 EST 2021

Am Mittwoch, den 24.02.2021, 16:21 +0100 schrieb Bruno Thomsen:


> No, this is not a regression from 5.10. It seems that many attempts to
> fix cdc-acm in the 5.x kernel series have failed to fix the root cause of
> these oops. I have not seen this on 4.14 and 4.19, but I have observed
> it on at least 5.3 and newer kernels in slight variations.
> I guess this is because cdc-acm is very common in the embedded
> ARM world and rarely used on servers or laptops. Combined with
> ARM devices still commonly use 4.x LTS kernels. Not sure if
> hardening options on the kernel has increased change of reproducing
> oops.

OK, so this is not an additional problem.
According to your logs, an URB that should have been killed wasn't.

> I am ready to test new patches and will continue to report oops

Could you test the attached patches?


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