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dkim=pass header.d=gmail.com header.s=20210112 header.b=R0iWBH+H; spf=pass (imf13.hostedemail.com: domain of andreyknvl@gmail.com designates 209.85.160.41 as permitted sender) smtp.mailfrom=andreyknvl@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Stat-Signature: mza36o5mzuyf5y4nxzbcgrex98rshdw8 X-Rspamd-Server: rspam10 X-HE-Tag: 1666898166-976015 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Oct 27, 2022 at 9:13 PM Kees Cook wrote: > > On Thu, Oct 27, 2022 at 09:05:45PM +0200, Andrey Konovalov wrote: > > On Sat, Oct 22, 2022 at 8:08 PM Kees Cook wrote: > > [...] > > > -/* Check that ksize() makes the whole object accessible. */ > > > +/* Check that ksize() does NOT unpoison whole object. */ > > > static void ksize_unpoisons_memory(struct kunit *test) > > > { > > > char *ptr; > > > @@ -791,15 +791,17 @@ static void ksize_unpoisons_memory(struct kunit *test) > > > > > > ptr = kmalloc(size, GFP_KERNEL); > > > KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); > > > + > > > real_size = ksize(ptr); > > > + KUNIT_EXPECT_GT(test, real_size, size); > > > > > > OPTIMIZER_HIDE_VAR(ptr); > > > > > > /* This access shouldn't trigger a KASAN report. */ > > > - ptr[size] = 'x'; > > > + ptr[size - 1] = 'x'; > > > > > > /* This one must. */ > > > - KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size]); > > > + KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size - 1]); > > > > How about also accessing ptr[size] here? It would allow for a more > > precise checking of the in-object redzone. > > Sure! Probably both ptr[size] and ptr[real_size -1], yes? Yes, sounds good. Thank you!