Re: [PATCH] Revert "i2c: dev: switch from register_chrdev to cdev API"

[Dan Carpenter]

On Sat, May 28, 2016 at 11:07:47AM +0200, Wolfram Sang wrote:
> This reverts commit d6760b14d4a1243f918d983bba1e35c5a5cd5a6d. When
> hitting Linus' tree, buildbots ran additional checks and found boot
> problems. Although Dan Carpenter provided an obvious fix already, I
> still could not reproduce one problem manually (at least not on a
> Saturday morning). So we'll try again later after some more
> investigation.
> 

These kinds of use after frees don't always cause a runtime problem.  I
found it using static analysis, but I bet you could detect it if you
enabled kasan.  The other option is to enable PAGE_POISONING?

regards,
dan carpenter