From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001 From: Shivank Garg Date: Sat, 22 Aug 2026 19:22:05 +0000 Subject: dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel() 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 Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com Reviewed-by: Frank Li Reviewed-by: Logan Gunthorpe Signed-off-by: Shivank Garg Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com Signed-off-by: Vinod Koul --- samples/trace_events/Makefile | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 samples/trace_events/Makefile (limited to 'samples/trace_events/Makefile') diff --git a/samples/trace_events/Makefile b/samples/trace_events/Makefile new file mode 100644 index 000000000..b3808bb4c --- /dev/null +++ b/samples/trace_events/Makefile @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0-only +# builds the trace events example kernel modules; +# then to use one (as root): insmod + +# If you include a trace header outside of include/trace/events +# then the file that does the #define CREATE_TRACE_POINTS must +# have that tracer file in its main search path. This is because +# define_trace.h will include it, and must be able to find it from +# the include/trace directory. +# +# Here trace-events-sample.c does the CREATE_TRACE_POINTS. +# +CFLAGS_trace-events-sample.o := -I$(src) +CFLAGS_trace_custom_sched.o := -I$(src) + +obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace-events-sample.o +obj-$(CONFIG_SAMPLE_TRACE_CUSTOM_EVENTS) += trace_custom_sched.o -- cgit v1.3.1