On Mon, Sep 03, 2018 at 04:32:48PM +0200, Jann Horn wrote:
> commit 342db04ae71273322f0011384a9ed414df8bdae4 upstream.
>
> show_opcodes() is used both for dumping kernel instructions and for dumping
> user instructions. If userspace causes #PF by jumping to a kernel address,
> show_opcodes() can be reached with regs->ip controlled by the user,
> pointing to kernel code. Make sure that userspace can't trick us into
> dumping kernel memory into dmesg.
>
> Manually backported: show_opcodes() has changed a bit in the meantime.
> I have manually tested the backport.
>
> Fixes: 7cccf0725cf7 ("x86/dumpstack: Add a show_ip() function")
> Cc: stable@xxxxxxxxxxxxxxx
> Link: https://lkml.kernel.org/r/20180828154901.112726-1-jannh@xxxxxxxxxx
> Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
> ---
> Since I manually backported this, I have removed all other
> sign-off/reviewed-by lines. I hope that's correct?
Yes, that's fine, but I added them back as this wasn't that different of
a backport :)
THanks for the patch, now queued up.
greg k-h
