From: Emil Tsalapatis <emil@etsalapatis.com>
Date: Mon, 2 Feb 2026 00:42:08 +0000 (-0500)
Subject: tools/sched_ext: Fix data header access during free in scx_sdt
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e06d54ea9a25e2925a31eb5410af0f16baa8f19;p=thirdparty%2Fkernel%2Flinux.git

tools/sched_ext: Fix data header access during free in scx_sdt

Fix a pointer arithmetic error in scx_sdt during freeing that
causes the allocator to use the wrong memory address for the
allocation's data header.

Fixes: 36929ebd17ae ("tools/sched_ext: add arena based scheduler")
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/tools/sched_ext/scx_sdt.bpf.c b/tools/sched_ext/scx_sdt.bpf.c
index d965f7d209def..31b09958e8d5f 100644
--- a/tools/sched_ext/scx_sdt.bpf.c
+++ b/tools/sched_ext/scx_sdt.bpf.c
@@ -312,7 +312,7 @@ int scx_alloc_free_idx(struct scx_allocator *alloc, __u64 idx)
 	pos = idx & mask;
 	data = chunk->data[pos];
 	if (likely(data)) {
-		data[pos] = (struct sdt_data) {
+		*data = (struct sdt_data) {
 			.tid.genn = data->tid.genn + 1,
 		};