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, 66 insertions, 0 deletions

diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
new file mode 100644
index 000000000..04ff92684
--- /dev/null
+++ b/tools/perf/util/top.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_TOP_H
+#define __PERF_TOP_H 1
+
+#include "tool.h"
+#include "evswitch.h"
+#include "annotate.h"
+#include "mutex.h"
+#include "ordered-events.h"
+#include "record.h"
+#include <linux/types.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <sys/ioctl.h>
+
+struct evlist;
+struct evsel;
+struct perf_session;
+
+struct perf_top {
+	struct perf_tool   tool;
+	struct evlist *evlist, *sb_evlist;
+	struct record_opts record_opts;
+	struct evswitch	   evswitch;
+	/*
+	 * Symbols will be added here in perf_event__process_sample and will
+	 * get out after decayed.
+	 */
+	u64		   samples, lost, lost_total, drop, drop_total;
+	u64		   kernel_samples, us_samples;
+	u64		   exact_samples;
+	u64		   guest_us_samples, guest_kernel_samples;
+	int		   print_entries, count_filter, delay_secs;
+	int		   max_stack;
+	bool		   hide_kernel_symbols, hide_user_symbols, zero;
+#ifdef HAVE_SLANG_SUPPORT
+	bool		   use_tui;
+#endif
+	bool		   use_stdio;
+	bool		   vmlinux_warned;
+	bool		   dump_symtab;
+	bool		   stitch_lbr;
+	struct hist_entry  *sym_filter_entry;
+	struct evsel 	   *sym_evsel;
+	struct perf_session *session;
+	struct winsize	   winsize;
+	int		   realtime_prio;
+	const char	   *sym_filter;
+	float		   min_percent;
+	unsigned int	   nr_threads_synthesize;
+	const char	   *uid_str;
+
+	struct {
+		struct ordered_events	*in;
+		struct ordered_events	 data[2];
+		bool			 rotate;
+		struct mutex mutex;
+		struct cond cond;
+	} qe;
+};
+
+#define CONSOLE_CLEAR ""
+
+size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size);
+void perf_top__reset_sample_counters(struct perf_top *top);
+#endif /* __PERF_TOP_H */