dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted

When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.

dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:

	slab-use-after-free in dma_chan_put+0x3e6/0x4c0
	Read of size 8 by task insmod/6319
	Freed by task 6319:
	  kfree+0x225/0x470
	  dma_chan_put+0x395/0x4c0
	  dmaengine_put+0xf8/0x160

Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device.

Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct")
Suggested-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/tools/perf/util/sample-raw.c b/tools/perf/util/sample-raw.c
new file mode 100644
index 000000000..f5ae9f468
--- /dev/null
+++ b/tools/perf/util/sample-raw.c
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include "sample-raw.h"
+
+#include <elf.h>
+#include <linux/string.h>
+
+#include "env.h"
+#include "evlist.h"
+#include "header.h"
+#include "session.h"
+
+/*
+ * Check platform the perf data file was created on and perform platform
+ * specific interpretation.
+ */
+void evlist__init_trace_event_sample_raw(struct evlist *evlist, struct perf_env *env)
+{
+	uint16_t e_machine = perf_env__e_machine(env, /*e_flags=*/NULL);
+
+	if (e_machine == EM_S390) {
+		evlist__set_trace_event_sample_raw(evlist, evlist__s390_sample_raw);
+	} else if (e_machine == EM_X86_64 || e_machine == EM_386) {
+		const char *cpuid = perf_env__cpuid(env);
+
+		if (cpuid && strstarts(cpuid, "AuthenticAMD") && evlist__has_amd_ibs(evlist))
+			evlist__set_trace_event_sample_raw(evlist, evlist__amd_sample_raw);
+	}
+}