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/vb2.h | 69 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 include/trace/events/vb2.h (limited to 'include/trace/events/vb2.h') diff --git a/include/trace/events/vb2.h b/include/trace/events/vb2.h new file mode 100644 index 000000000..a40146dea --- /dev/null +++ b/include/trace/events/vb2.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM vb2 + +#if !defined(_TRACE_VB2_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_VB2_H + +#include +#include + +DECLARE_EVENT_CLASS(vb2_event_class, + TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb), + TP_ARGS(q, vb), + + TP_STRUCT__entry( + __field(void *, owner) + __field(u32, queued_count) + __field(int, owned_by_drv_count) + __field(u32, index) + __field(u32, type) + __field(u32, bytesused) + __field(u64, timestamp) + ), + + TP_fast_assign( + __entry->owner = q->owner; + __entry->queued_count = q->queued_count; + __entry->owned_by_drv_count = + atomic_read(&q->owned_by_drv_count); + __entry->index = vb->index; + __entry->type = vb->type; + __entry->bytesused = vb->planes[0].bytesused; + __entry->timestamp = vb->timestamp; + ), + + TP_printk("owner = %p, queued = %u, owned_by_drv = %d, index = %u, " + "type = %u, bytesused = %u, timestamp = %llu", __entry->owner, + __entry->queued_count, + __entry->owned_by_drv_count, + __entry->index, __entry->type, + __entry->bytesused, + __entry->timestamp + ) +) + +DEFINE_EVENT(vb2_event_class, vb2_buf_done, + TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb), + TP_ARGS(q, vb) +); + +DEFINE_EVENT(vb2_event_class, vb2_buf_queue, + TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb), + TP_ARGS(q, vb) +); + +DEFINE_EVENT(vb2_event_class, vb2_dqbuf, + TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb), + TP_ARGS(q, vb) +); + +DEFINE_EVENT(vb2_event_class, vb2_qbuf, + TP_PROTO(struct vb2_queue *q, struct vb2_buffer *vb), + TP_ARGS(q, vb) +); + +#endif /* if !defined(_TRACE_VB2_H) || defined(TRACE_HEADER_MULTI_READ) */ + +/* This part must be outside protection */ +#include -- cgit v1.3.1