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/uapi/misc/ocxl.h | 80 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 include/uapi/misc/ocxl.h (limited to 'include/uapi/misc/ocxl.h') diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h new file mode 100644 index 000000000..6d29a60a8 --- /dev/null +++ b/include/uapi/misc/ocxl.h @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +/* Copyright 2017 IBM Corp. */ +#ifndef _UAPI_MISC_OCXL_H +#define _UAPI_MISC_OCXL_H + +#include +#include + +enum ocxl_event_type { + OCXL_AFU_EVENT_XSL_FAULT_ERROR = 0, +}; + +#define OCXL_KERNEL_EVENT_FLAG_LAST 0x0001 /* This is the last event pending */ + +struct ocxl_kernel_event_header { + __u16 type; + __u16 flags; + __u32 reserved; +}; + +struct ocxl_kernel_event_xsl_fault_error { + __u64 addr; + __u64 dsisr; + __u64 count; + __u64 reserved; +}; + +struct ocxl_ioctl_attach { + __u64 amr; + __u64 reserved1; + __u64 reserved2; + __u64 reserved3; +}; + +struct ocxl_ioctl_metadata { + __u16 version; /* struct version, always backwards compatible */ + + /* Version 0 fields */ + __u8 afu_version_major; + __u8 afu_version_minor; + __u32 pasid; /* PASID assigned to the current context */ + + __u64 pp_mmio_size; /* Per PASID MMIO size */ + __u64 global_mmio_size; + + /* End version 0 fields */ + + __u64 reserved[13]; /* Total of 16*u64 */ +}; + +struct ocxl_ioctl_p9_wait { + __u16 thread_id; /* The thread ID required to wake this thread */ + __u16 reserved1; + __u32 reserved2; + __u64 reserved3[3]; +}; + +#define OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT 0x01 +struct ocxl_ioctl_features { + __u64 flags[4]; +}; + +struct ocxl_ioctl_irq_fd { + __u64 irq_offset; + __s32 eventfd; + __u32 reserved; +}; + +/* ioctl numbers */ +#define OCXL_MAGIC 0xCA +/* AFU devices */ +#define OCXL_IOCTL_ATTACH _IOW(OCXL_MAGIC, 0x10, struct ocxl_ioctl_attach) +#define OCXL_IOCTL_IRQ_ALLOC _IOR(OCXL_MAGIC, 0x11, __u64) +#define OCXL_IOCTL_IRQ_FREE _IOW(OCXL_MAGIC, 0x12, __u64) +#define OCXL_IOCTL_IRQ_SET_FD _IOW(OCXL_MAGIC, 0x13, struct ocxl_ioctl_irq_fd) +#define OCXL_IOCTL_GET_METADATA _IOR(OCXL_MAGIC, 0x14, struct ocxl_ioctl_metadata) +#define OCXL_IOCTL_ENABLE_P9_WAIT _IOR(OCXL_MAGIC, 0x15, struct ocxl_ioctl_p9_wait) +#define OCXL_IOCTL_GET_FEATURES _IOR(OCXL_MAGIC, 0x16, struct ocxl_ioctl_features) + +#endif /* _UAPI_MISC_OCXL_H */ -- cgit v1.3.1