Re: [PATCH] x86/mce/amd: Fix kobject lifetime

[Borislav Petkov]

On Fri, Feb 14, 2020 at 09:28:01AM +0100, Borislav Petkov wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> 
> Accessing the MCA thresholding controls in sysfs concurrently with CPU
> hotplug can lead to a couple of KASAN-reported issues:
> 
>   BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180
>   Read of size 8 at addr ffff888367578940 by task grep/4019
> 
> and
> 
>   BUG: KASAN: use-after-free in show_error_count+0x15c/0x180
>   Read of size 2 at addr ffff888368a05514 by task grep/4454
> 
> for example. Both result from the fact that the threshold block
> creation/teardown code frees the descriptor memory itself instead of
> defining proper ->release function and leaving it to the driver core to
> take care of that, after all sysfs accesses have completed.
> 
> Do that and get rid of the custom freeing code, fixing the above UAFs in
> the process.
> 
>   [ bp: write commit message. ]
> 
> Fixes: 95268664390b ("[PATCH] x86_64: mce_amd support for family 0x10 processors")
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>

Damn git-send-email: it read out Cc: stable and added it to the Cc list.
I've added

suppresscc = bodycc

to my .gitconfig.

Sorry stable guys.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette