6.12-stable patches

added patches:
	sched_ext-validate-prev_cpu-in-scx_bpf_select_cpu_dfl.patch

diff --git a/queue-6.12/sched_ext-validate-prev_cpu-in-scx_bpf_select_cpu_dfl.patch b/queue-6.12/sched_ext-validate-prev_cpu-in-scx_bpf_select_cpu_dfl.patch
new file mode 100644 (file)
index 0000000..ec158dc
--- /dev/null
+++ b/queue-6.12/sched_ext-validate-prev_cpu-in-scx_bpf_select_cpu_dfl.patch
@@ -0,0 +1,37 @@
+From 9360dfe4cbd62ff1eb8217b815964931523b75b3 Mon Sep 17 00:00:00 2001
+From: Andrea Righi <arighi@nvidia.com>
+Date: Mon, 3 Mar 2025 18:51:59 +0100
+Subject: sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()
+
+From: Andrea Righi <arighi@nvidia.com>
+
+commit 9360dfe4cbd62ff1eb8217b815964931523b75b3 upstream.
+
+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 <arighi@nvidia.com>
+Signed-off-by: Tejun Heo <tj@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/sched/ext.c |    3 +++
+ 1 file changed, 3 insertions(+)
+
+--- a/kernel/sched/ext.c
++++ b/kernel/sched/ext.c
+@@ -6052,6 +6052,9 @@ __bpf_kfunc_start_defs();
+ __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))
++              goto prev_cpu;
++
+       if (!static_branch_likely(&scx_builtin_idle_enabled)) {
+               scx_ops_error("built-in idle tracking is disabled");
+               goto prev_cpu;

diff --git a/queue-6.12/series b/queue-6.12/series
index 6449e02f44d2a236bee5a59dda70763c7a621d0d..bc2a1abe9c7a141e05ae1b32c1ab735cdc639972 100644 (file)
--- a/queue-6.12/series
+++ b/queue-6.12/series
@@ -151,3 +151,4 @@ kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.smen.patch
 kvm-arm64-refactor-exit-handlers.patch
 kvm-arm64-mark-some-header-functions-as-inline.patch
 kvm-arm64-eagerly-switch-zcr_el-1-2.patch
+sched_ext-validate-prev_cpu-in-scx_bpf_select_cpu_dfl.patch