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X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Oct 2025 12:41:52.0355 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 827a9a89-2e14-406f-7e2e-08de17b1b37f X-MS-Exchange-CrossTenant-Id: f34e5979-57d9-4aaa-ad4d-b122a662184d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=f34e5979-57d9-4aaa-ad4d-b122a662184d;Ip=[4.158.2.129];Helo=[outbound-uk1.az.dlp.m.darktrace.com] X-MS-Exchange-CrossTenant-AuthSource: DB3PEPF0000885F.eurprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: GVXPR08MB10613 Hi Harry, > On Wed, Oct 29, 2025 at 07:19:29PM +0100, Andrey Ryabinin wrote: > > > > > > On 10/27/25 1:28 PM, Harry Yoo wrote: > > > > > slab->obj_exts |= MEMCG_DATA_OBJEXTS; > > > slab_set_stride(slab, sizeof(struct slabobj_ext)); > > > + } else if (obj_exts_in_object(s)) { > > > + unsigned int offset = obj_exts_offset_in_object(s); > > > + > > > + slab->obj_exts = (unsigned long)slab_address(slab); > > > + slab->obj_exts += s->red_left_pad; > > > + slab->obj_exts += obj_exts_offset_in_object(s); > > > + if (IS_ENABLED(CONFIG_MEMCG)) > > > + slab->obj_exts |= MEMCG_DATA_OBJEXTS; > > > + slab_set_stride(slab, s->size); > > > + > > > + for_each_object(addr, s, slab_address(slab), slab->objects) { > > > + kasan_unpoison_range(addr + offset, > > > + sizeof(struct slabobj_ext)); > > > > Is this leftover from previous version? Otherwise I don't get why we unpoison this. > > Oh god, yes! Thanks for catching. Will fix in the next version. > Not only this, there would be possible case for WARN_ON() in the kasan_unpoison_range() for unaligned address with KASAN_GRANULE_SIZE when: - No debug information. - object size = 24 byte. - align = 32 bytes. - sizeof(struct slabobj_ext) = 8 (CONFIG_MEMCG=y && CONFIG_MEM_ALLOC_PROFILING=n) - using KASAN_HW_TAG (KASAN_GRANULE_SIZE = 16 bytes). Thanks. -- Sincerely, Yeoreum Yun