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 --- include/trace/events/devfreq.h | 68 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 include/trace/events/devfreq.h (limited to 'include/trace/events/devfreq.h') diff --git a/include/trace/events/devfreq.h b/include/trace/events/devfreq.h new file mode 100644 index 000000000..6cbc4d59f --- /dev/null +++ b/include/trace/events/devfreq.h @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM devfreq + +#if !defined(_TRACE_DEVFREQ_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_DEVFREQ_H + +#include +#include + +TRACE_EVENT(devfreq_frequency, + TP_PROTO(struct devfreq *devfreq, unsigned long freq, + unsigned long prev_freq), + + TP_ARGS(devfreq, freq, prev_freq), + + TP_STRUCT__entry( + __string(dev_name, dev_name(&devfreq->dev)) + __field(unsigned long, freq) + __field(unsigned long, prev_freq) + __field(unsigned long, busy_time) + __field(unsigned long, total_time) + ), + + TP_fast_assign( + __assign_str(dev_name); + __entry->freq = freq; + __entry->prev_freq = prev_freq; + __entry->busy_time = devfreq->last_status.busy_time; + __entry->total_time = devfreq->last_status.total_time; + ), + + TP_printk("dev_name=%-30s freq=%-12lu prev_freq=%-12lu load=%-2lu", + __get_str(dev_name), __entry->freq, __entry->prev_freq, + __entry->total_time == 0 ? 0 : + (100 * __entry->busy_time) / __entry->total_time) +); + +TRACE_EVENT(devfreq_monitor, + TP_PROTO(struct devfreq *devfreq), + + TP_ARGS(devfreq), + + TP_STRUCT__entry( + __field(unsigned long, freq) + __field(unsigned long, busy_time) + __field(unsigned long, total_time) + __field(unsigned int, polling_ms) + __string(dev_name, dev_name(&devfreq->dev)) + ), + + TP_fast_assign( + __entry->freq = devfreq->previous_freq; + __entry->busy_time = devfreq->last_status.busy_time; + __entry->total_time = devfreq->last_status.total_time; + __entry->polling_ms = devfreq->profile->polling_ms; + __assign_str(dev_name); + ), + + TP_printk("dev_name=%-30s freq=%-12lu polling_ms=%-3u load=%-2lu", + __get_str(dev_name), __entry->freq, __entry->polling_ms, + __entry->total_time == 0 ? 0 : + (100 * __entry->busy_time) / __entry->total_time) +); +#endif /* _TRACE_DEVFREQ_H */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1