Messages in this thread | | | Date | Wed, 05 Sep 2012 15:06:03 -0700 | From | John Johansen <> | Subject | Re: [PATCH] Yama: handle 32-bit userspace prctl |
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On 08/27/2012 11:38 AM, Kees Cook wrote: > When running a 64-bit kernel and receiving prctls from a 32-bit > userspace, the "-1" used as an unsigned long will end up being > misdetected. The kernel is looking for 0xffffffffffffffff instead of > 0xffffffff. Since prctl lacks a distinct compat interface, Yama needs > to handle this translation itself. As such, support either value as > meaning PR_SET_PTRACER_ANY, to avoid breaking the ABI for 64-bit. > > Signed-off-by: Kees Cook <keescook@chromium.org> > Cc: stable@vger.kernel.org > --- > security/yama/yama_lsm.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c > index 0cc99a3..dcd6178 100644 > --- a/security/yama/yama_lsm.c > +++ b/security/yama/yama_lsm.c > @@ -143,7 +143,7 @@ static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, > if (arg2 == 0) { > yama_ptracer_del(NULL, myself); > rc = 0; > - } else if (arg2 == PR_SET_PTRACER_ANY) { > + } else if (arg2 == PR_SET_PTRACER_ANY || (int)arg2 == -1) { > rc = yama_ptracer_add(NULL, myself); > } else { > struct task_struct *tracer; >
yeah this looks good it should at least hit stable
Acked-by: John Johansen <john.johansen@canonical.com>
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