On Sat, Dec 28, 2019 at 1:18 PM Tycho Andersen <tycho@xxxxxxxx> wrote: > > On Sat, Dec 28, 2019 at 01:48:39AM +0000, Sargun Dhillon wrote: > > The seccomp_notif structure should be zeroed out prior to calling the > > SECCOMP_IOCTL_NOTIF_RECV ioctl. Previously, the kernel did not check > > whether these structures were zeroed out or not, so these worked. > > > > Signed-off-by: Sargun Dhillon <sargun@xxxxxxxxx> > > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > > --- > > samples/seccomp/user-trap.c | 2 +- > > tools/testing/selftests/seccomp/seccomp_bpf.c | 2 ++ > > 2 files changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/samples/seccomp/user-trap.c b/samples/seccomp/user-trap.c > > index 6d0125ca8af7..0ca8fb37cd79 100644 > > --- a/samples/seccomp/user-trap.c > > +++ b/samples/seccomp/user-trap.c > > @@ -298,7 +298,6 @@ int main(void) > > req = malloc(sizes.seccomp_notif); > > if (!req) > > goto out_close; > > - memset(req, 0, sizeof(*req)); > > > > resp = malloc(sizes.seccomp_notif_resp); > > if (!resp) > > @@ -306,6 +305,7 @@ int main(void) > > memset(resp, 0, sizeof(*resp)); > > I know it's unrelated, but it's probably worth sending a patch to fix > this to be sizes.seccomp_notif_resp instead of sizeof(*resp), since if > the kernel is older this will over-zero things. I can do that, or you > can add the patch to this series, just let me know which. I was thinking about this, and initially, I chose to make the smaller change. I think it might make more sense to combine the patch, given that the memset behaviour is "incorrect" if we do it based on sizeof(*req), or sizeof(*resp). I'll go ahead and respin this patch with the change to call memset based on sizes. > > But in any case, this patch is: > > Reviewed-by: Tycho Andersen <tycho@xxxxxxxx> > > Cheers, > > Tycho
