Messages in this thread | | | Date | Thu, 16 Dec 2021 16:02:33 -0800 | From | Kees Cook <> | Subject | Re: [PATCH] lkdtm: avoid printk() in recursive_loop() |
| |
On Thu, Dec 16, 2021 at 12:16:19PM +0100, Ard Biesheuvel wrote: > On Thu, 7 Oct 2021 at 18:59, Kees Cook <keescook@chromium.org> wrote: > > > > On Thu, 7 Oct 2021 10:12:35 +0200, Ard Biesheuvel wrote: > > > The recursive_loop() function is intended as a diagnostic to ensure that > > > exhausting the stack is caught and mitigated. Currently, it uses > > > pr_info() to ensure that the function has side effects that the compiler > > > cannot simply optimize away, so that the stack footprint does not get > > > reduced inadvertently. > > > > > > The typical mitigation for stack overflow is to kill the task, and this > > > overflow may occur inside the call to pr_info(), which means it could be > > > holding the console lock when this happens. This means that the console > > > lock is never going to be released again, preventing the diagnostic > > > prints related to the stack overflow handling from being visible on the > > > console. > > > > > > [...] > > > > Applied to for-next/lkdtm, thanks! > > > > [1/1] lkdtm: avoid printk() in recursive_loop() > > https://git.kernel.org/kees/c/700fa7d22233 > > > > Ping?
Eek, I didn't send my -next pull to Greg yet. Done now; thanks for the ping! :)
-Kees
-- Kees Cook
| |