Hi Kees, > Date: 2026-11-10 14:06:07-0800 > From: Kees Cook > > On Wed, Nov 04, 2026 at 12:17:00PM +0100, Alejandro Colomar wrote: > > > No current caller checks for overflow after terminating a seq_buf that > > > can be left exactly full, so none of them behaves differently. > > > > Okay for this patch, but still some question: > > > > Since data truncation is almost always wrong, is it a bug that those > > users are not verifying that no overflow happened? Or do they have a > > good reason to not verify? > > Right, this would need a case-by-case analysis. Some expect it and some > don't. This change to the API is to make it defensive in the general > case without making existing truncation worse. Agree. In shadow-utils we have the same approach. We're first hardening the writes to avoid overflows, and are leaving the truncations unreported as they were before, since that needs a case-by-case analysis. I won't give my reviewed-by, since I fundamentally think this is building on the mistake of having sizes and lengths instead of pointers. But I _think_ this patch is good, FWIW. Have a lovely night! Alex > > -Kees > > -- > Kees Cook --