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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?fjJYMvQyL8qZDNk9Uam+QaPPij3bUR/eDODj2Xr3u1EXEAlLK0mMzVOQmJyO?= =?us-ascii?Q?/0MqOSdRsq5Ucs044TAVZb+liNnEV3nACnmb9AYFfiZQAqWQyQ+SjVSGMH21?= =?us-ascii?Q?VDnGyWRj/iRUQbiWdjdX/5CzFNdkplxHEK/9mZ8hqEXQ+rcfmFFMWNqmbqyZ?= =?us-ascii?Q?BAeLrLGKllbugbuxTb3WIx3VFQi6QvXGG0I605xjx1f4aFk59j8g2JfWmnRX?= =?us-ascii?Q?px5WezIyYYCth+lzd6ZYfbccKB29de5DqTzbcuQHBCZ27j4Y34QIWytX/Yun?= =?us-ascii?Q?Q1+FtglmwNW+XCuxh8JkrZEXbxEmJcFGQBDVza9XmI6ZKJdPfiX5S+M8n6R1?= =?us-ascii?Q?0LJdMKVFfFp3PEEm00A/giMO7Shriuxm3oVNe1dbxwoMvv5/T20hIUet6rDf?= =?us-ascii?Q?BLD94Tx4ivnbLBIRrp8mDpgKM1n5KJ/qO9UxvRhN968q54+gNejiuTC459Ez?= =?us-ascii?Q?tBOUXmaoGxYRFVtSuME8l9tuZla4V8XKVhrkvRoGh7CojFi7SmWm7s8tX/do?= =?us-ascii?Q?l0orZ3ets5gRTYx8K5KaC8kBuIh4kMPCdXKNsU6vr2aeYEOXI0sIK4eMnkfE?= =?us-ascii?Q?ZsB3PxKwTFb/Q9WJ16vhDjvl1Se28+EsfdJ2+5Xw2ciucnKtO8qBMClNnwqw?= =?us-ascii?Q?kp6XiYrXc7vvncRm4CDpQVRmtCGspLHfCTRfVkpk9AXOi1rXjEfSGYdro2W1?= =?us-ascii?Q?VBJ8KMVeUHsdSnGv3wafjAJcEXQGjVQIf6fEtObj64iaFmxzDO4Q/QJPzz4T?= =?us-ascii?Q?jEvsBF3jW7BvZ3wsUClUM01XsAojqDc/PEwTo55nkFmd94EQp1y4LnxwQ9Aa?= =?us-ascii?Q?TTl/KScB2vEOGttBX+Q50LiEBIyFyp9QXaDYgjr1SEl24Od4fCkWEgIUOqek?= =?us-ascii?Q?W7TKVE7u1VbDlGTO76YaZUjwIptjccOTjsPTNAL47PFXFhckvpUPqtOgkRUe?= =?us-ascii?Q?OETnKDYfv0dft3HsageN+PTF5VCfnbrEtBEBls3YYEk83fMrmWK5O5JuNgd5?= =?us-ascii?Q?lDzUqOU8nKlaNjqVp4DGCExPafOBu8kZYtaZSgzOhN7th04cDsSefarZTBcv?= =?us-ascii?Q?VBvzbS9CtXKvCSeqSy59US7gAJt3zYQlqyJbDtn4QcgSlCNF3ZLH37G4JHa4?= =?us-ascii?Q?7s6DSHH0bqDw7TW2ck/eHn/jlRwwKA81iG31yFgu21sxK8U+bOLyH0CJs67s?= =?us-ascii?Q?f+oieAvrZbMBxtJsQckeuncdJsaK3rdGDPEYxpGf+l2151m3XozAb838zuWS?= =?us-ascii?Q?o1hMjIk9EvgWS3pSn3SE3S2ALVVrrNm4xokUe2g2EssySYTl/LgN56FjKINx?= =?us-ascii?Q?feL75RqJLgCJVfDEXtBqYlwRBA0GQDh8zzsxwSDfKRf7cbm6WxuR4mNmpB3Q?= =?us-ascii?Q?o7jRcbbW8UMK0Z7vS3yEcLi2YyKzaVy94QKhTAQ0f0AH0khOOKVPQmcPbukn?= =?us-ascii?Q?YrS5VOY6biyigTwl8zCPb0bKJUhCZaPys2esiYRcm0Iv5uDXISdhXmtOrfbP?= =?us-ascii?Q?cxvpNhOghAW9SwdliHR1exODoAAcemGDQKVBVy3oi7RnKFNDM13Gbj+cjKox?= =?us-ascii?Q?LQzSevuvUbqhwZmhiWu1enFfoOWVAVdbaJJVzF6T?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 54c40716-aeec-442e-ec95-08dd5a786b31 X-MS-Exchange-CrossTenant-AuthSource: CY5PR12MB6405.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Mar 2025 17:25:39.9000 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: i6wtr2peWm95Nr//a9FTksENVObZWqaXyC+gbHoAp5x2e74oMosEJOjlLrWwTCiPv7U3E2MasQrD7cg7BfCXRA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR12MB7888 On Mon, Mar 03, 2025 at 06:11:15AM -1000, Tejun Heo wrote: > Hello, > > On Sun, Mar 02, 2025 at 11:09:03PM +0100, Andrea Righi wrote: > > If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids > > range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel > > crash. > > > > To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and > > trigger an scx error if an invalid CPU is specified. > > > > Fixes: f0e1a0643a59b ("sched_ext: Implement BPF extensible scheduler class") > > Cc: stable@vger.kernel.org # v6.12+ > > Signed-off-by: Andrea Righi > > --- > > kernel/sched/ext.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > > index 0f1da199cfc7c..88b2ea58ff942 100644 > > --- a/kernel/sched/ext.c > > +++ b/kernel/sched/ext.c > > @@ -6422,6 +6422,11 @@ static bool check_builtin_idle_enabled(void) > > __bpf_kfunc s32 scx_bpf_select_cpu_dfl(struct task_struct *p, s32 prev_cpu, > > u64 wake_flags, bool *is_idle) > > { > > + if (!ops_cpu_valid(prev_cpu, NULL)) { > > + prev_cpu = cpumask_any(p->cpus_ptr); > > + goto prev_cpu; > > I'd just return the invalid prev_cpu. The scheduler is getting aborted > anyway. > > Thanks. Yeah, makes sense. I'll send a new patch soon. Thanks, -Andrea