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authorShivank Garg <shivankg@amd.com>2026-08-22 19:22:05 +0000
committerVinod Koul <vkoul@kernel.org>2026-09-09 17:51:44 +0530
commite873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch)
treecc1ce1567f5b982359331863ebd9da38741f8d2e /Documentation/ABI/testing/debugfs-scmi
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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>
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+What: /sys/kernel/debug/scmi/<n>/instance_name
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: The name of the underlying SCMI instance <n> described by
+ all the debugfs accessors rooted at /sys/kernel/debug/scmi/<n>,
+ expressed as the full name of the top DT SCMI node under which
+ this SCMI instance is rooted.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/atomic_threshold_us
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: An optional time value, expressed in microseconds, representing,
+ on this SCMI instance <n>, the threshold above which any SCMI
+ command, advertised to have an higher-than-threshold execution
+ latency, should not be considered for atomic mode of operation,
+ even if requested.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/transport/type
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: A string representing the type of transport configured for this
+ SCMI instance <n>.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/transport/is_atomic
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: A boolean stating if the transport configured on the underlying
+ SCMI instance <n> is capable of atomic mode of operation.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/transport/max_rx_timeout_ms
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: Timeout in milliseconds allowed for SCMI synchronous replies
+ for the currently configured SCMI transport for instance <n>.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/transport/max_msg_size
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: Max message size of allowed SCMI messages for the currently
+ configured SCMI transport for instance <n>.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/transport/tx_max_msg
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: Max number of concurrently allowed in-flight SCMI messages for
+ the currently configured SCMI transport for instance <n> on the
+ TX channels.
+Users: Debugging, any userspace test suite
+
+What: /sys/kernel/debug/scmi/<n>/transport/rx_max_msg
+Date: March 2023
+KernelVersion: 6.3
+Contact: cristian.marussi@arm.com
+Description: Max number of concurrently allowed in-flight SCMI messages for
+ the currently configured SCMI transport for instance <n> on the
+ RX channels.
+Users: Debugging, any userspace test suite