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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: CX1hQpquMuuUfWXfH+uQF/ykvpqt7Yz+8qd78pSSK1fqL78IlYySIbttkocjjuiQaNV2wTvChH6q3Dc2o7oQc0zBgK9oAS4OBYvvYIh7ksHdyA4PHjujUXmEcwrsaTYPwySNMKkyhPdhuNcqFx3VLZA39dlI9yFBM2ay4jZxbG7vj+BfGiJW8bk8Q9cJuFGW9yAWRrNADY+DLVCKKI96tVKEfUelM2109VMfCjtpVTW2euUZXiI9Is7dcCgUscTl5SMSoVrLfRDFqi2c+xp9AaVlcggwr6NRclC6LOFbb0OvuK9WxxMlwRK0b2VgZdmrQ68chMYnxyXbp9+7yTNsOTtjNPejqUnHDvnGda3X2if/AtC7e7/3RsM2wJ4kbbtC78AJjxOihmYq7YknaTrkD/kgZYQ6sgUZsDJi/cMuRKBrS7ew0W38RjxezU3RS64n X-OriginatorOrg: arm.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Mar 2026 14:54:55.3172 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8452e464-9d4b-4df4-e5f3-08de88ec2563 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: DU2PEPF00028D13.eurprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB9PR08MB7399 On 20/03/2026 3:10 am, Andrew Morton wrote: > * # Be careful, this email looks suspicious; * Out of Character: The sender is exhibiting a significant deviation from their usual behavior, this may indicate that their account has been compromised. Be extra cautious before opening links or attachments. * > On Thu, 19 Mar 2026 11:49:43 +0000 Muhammad Usama Anjum wrote: > >> Stacks and page tables are always accessed with the match‑all tag, >> so assigning a new random tag every time at allocation and setting >> invalid tag at deallocation time, just adds overhead without improving >> the detection. >> >> With __GFP_SKIP_KASAN the page keeps its poison tag and KASAN_TAG_KERNEL >> (match-all tag) is stored in the page flags while keeping the poison tag >> in the hardware. The benefit of it is that 256 tag setting instruction >> per 4 kB page aren't needed at allocation and deallocation time. >> >> Thus match‑all pointers still work, while non‑match tags (other than >> poison tag) still fault. >> >> __GFP_SKIP_KASAN only skips for KASAN_HW_TAGS mode, so coverage is >> unchanged. >> > > Some questions from Sashiko: > https://uk01.z.antigena.com/l/sS6fsklhbbK-vAbd4-t3S20GiqcWENbKuEm9JdfcHhXGvSkAuP_tTYRVNNEFkNyqNy6Th_W67uq4HpyPCykcGaYKaeMj7OPiFdbYLta2AQ6H4~yy59q32QAKn-zpc1DtUKnRNXkTGRIvJMOH217hIWTkitNDDPLzALLhD6vG1MnteYIid8KfwK4pfDahLHbmvBU1WWp6d3BG53WUdBJ4ONjb2PDTe4JdIvW0uWnju-HL5hb > I've updated descriptions/patches in answer to those concerns. Thanks, Usama