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/percpu.h | 137 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 include/trace/events/percpu.h (limited to 'include/trace/events/percpu.h') diff --git a/include/trace/events/percpu.h b/include/trace/events/percpu.h new file mode 100644 index 000000000..5b8211ca8 --- /dev/null +++ b/include/trace/events/percpu.h @@ -0,0 +1,137 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM percpu + +#if !defined(_TRACE_PERCPU_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PERCPU_H + +#include +#include + +TRACE_EVENT(percpu_alloc_percpu, + + TP_PROTO(unsigned long call_site, + bool reserved, bool is_atomic, size_t size, + size_t align, void *base_addr, int off, + void __percpu *ptr, size_t bytes_alloc, gfp_t gfp_flags), + + TP_ARGS(call_site, reserved, is_atomic, size, align, base_addr, off, + ptr, bytes_alloc, gfp_flags), + + TP_STRUCT__entry( + __field( unsigned long, call_site ) + __field( bool, reserved ) + __field( bool, is_atomic ) + __field( size_t, size ) + __field( size_t, align ) + __field( void *, base_addr ) + __field( int, off ) + __field( void __percpu *, ptr ) + __field( size_t, bytes_alloc ) + __field( unsigned long, gfp_flags ) + ), + TP_fast_assign( + __entry->call_site = call_site; + __entry->reserved = reserved; + __entry->is_atomic = is_atomic; + __entry->size = size; + __entry->align = align; + __entry->base_addr = base_addr; + __entry->off = off; + __entry->ptr = ptr; + __entry->bytes_alloc = bytes_alloc; + __entry->gfp_flags = (__force unsigned long)gfp_flags; + ), + + TP_printk("call_site=%pS reserved=%d is_atomic=%d size=%zu align=%zu base_addr=%p off=%d ptr=%p bytes_alloc=%zu gfp_flags=%s", + (void *)__entry->call_site, + __entry->reserved, __entry->is_atomic, + __entry->size, __entry->align, + __entry->base_addr, __entry->off, __entry->ptr, + __entry->bytes_alloc, show_gfp_flags(__entry->gfp_flags)) +); + +TRACE_EVENT(percpu_free_percpu, + + TP_PROTO(void *base_addr, int off, void __percpu *ptr), + + TP_ARGS(base_addr, off, ptr), + + TP_STRUCT__entry( + __field( void *, base_addr ) + __field( int, off ) + __field( void __percpu *, ptr ) + ), + + TP_fast_assign( + __entry->base_addr = base_addr; + __entry->off = off; + __entry->ptr = ptr; + ), + + TP_printk("base_addr=%p off=%d ptr=%p", + __entry->base_addr, __entry->off, __entry->ptr) +); + +TRACE_EVENT(percpu_alloc_percpu_fail, + + TP_PROTO(bool reserved, bool is_atomic, size_t size, size_t align), + + TP_ARGS(reserved, is_atomic, size, align), + + TP_STRUCT__entry( + __field( bool, reserved ) + __field( bool, is_atomic ) + __field( size_t, size ) + __field( size_t, align ) + ), + + TP_fast_assign( + __entry->reserved = reserved; + __entry->is_atomic = is_atomic; + __entry->size = size; + __entry->align = align; + ), + + TP_printk("reserved=%d is_atomic=%d size=%zu align=%zu", + __entry->reserved, __entry->is_atomic, + __entry->size, __entry->align) +); + +TRACE_EVENT(percpu_create_chunk, + + TP_PROTO(void *base_addr), + + TP_ARGS(base_addr), + + TP_STRUCT__entry( + __field( void *, base_addr ) + ), + + TP_fast_assign( + __entry->base_addr = base_addr; + ), + + TP_printk("base_addr=%p", __entry->base_addr) +); + +TRACE_EVENT(percpu_destroy_chunk, + + TP_PROTO(void *base_addr), + + TP_ARGS(base_addr), + + TP_STRUCT__entry( + __field( void *, base_addr ) + ), + + TP_fast_assign( + __entry->base_addr = base_addr; + ), + + TP_printk("base_addr=%p", __entry->base_addr) +); + +#endif /* _TRACE_PERCPU_H */ + +#include -- cgit v1.3.1