Re: [PATCH] panic: Taint kernel if fault injection has been used

[Google]

On Fri, 2 Dec 2022 07:33:11 +0100
Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:

> On Fri, Dec 02, 2022 at 01:45:59PM +0900, Masami Hiramatsu (Google) wrote:
> > From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
> > 
> > Since the function error injection framework in the fault injection
> > subsystem can change the function code flow forcibly, it may cause
> > unexpected behavior (and that is the purpose of this feature) even
> > if it is applied to the ALLOW_ERROR_INJECTION functions.
> > So this feature must be used only for debugging or testing purpose.
> > 
> > To identify this in the kernel oops message, add a new taint flag
> > for the fault injection. This taint flag will be set by either
> > function error injection is used or the BPF use the kprobe_override
> > on error injectable functions (identified by ALLOW_ERROR_INJECTION).
> > 
> > Link: https://lore.kernel.org/all/20221121104403.1545f9b5@xxxxxxxxxxxxxxxxxx/T/#u
> > 
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
> > ---
> >  Documentation/admin-guide/tainted-kernels.rst |    5 +++++
> >  include/linux/panic.h                         |    3 ++-
> >  kernel/fail_function.c                        |    2 ++
> >  kernel/panic.c                                |    1 +
> >  kernel/trace/bpf_trace.c                      |    2 ++
> >  5 files changed, 12 insertions(+), 1 deletion(-)
> 
> I think you forgot to also update tools/debugging/kernel-chktaint with
> this new entry :(

Oops, thanks for pointing!
Let me update the patch.


-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>