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/hyperv/hvgdk_ext.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 include/hyperv/hvgdk_ext.h (limited to 'include/hyperv/hvgdk_ext.h') diff --git a/include/hyperv/hvgdk_ext.h b/include/hyperv/hvgdk_ext.h new file mode 100644 index 000000000..641b591ee --- /dev/null +++ b/include/hyperv/hvgdk_ext.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Type definitions for the Microsoft Hypervisor. + */ +#ifndef _HV_HVGDK_EXT_H +#define _HV_HVGDK_EXT_H + +#include "hvgdk_mini.h" + +/* Extended hypercalls */ +#define HV_EXT_CALL_QUERY_CAPABILITIES 0x8001 +#define HV_EXT_CALL_MEMORY_HEAT_HINT 0x8003 + +/* Extended hypercalls */ +enum { /* HV_EXT_CALL */ + HV_EXTCALL_QUERY_CAPABILITIES = 0x8001, + HV_EXTCALL_MEMORY_HEAT_HINT = 0x8003, +}; + +/* HV_EXT_OUTPUT_QUERY_CAPABILITIES */ +#define HV_EXT_CAPABILITY_MEMORY_COLD_DISCARD_HINT BIT(8) + +enum { /* HV_EXT_MEMORY_HEAT_HINT_TYPE */ + HV_EXTMEM_HEAT_HINT_COLD = 0, + HV_EXTMEM_HEAT_HINT_HOT = 1, + HV_EXTMEM_HEAT_HINT_COLD_DISCARD = 2, + HV_EXTMEM_HEAT_HINT_MAX +}; + +/* + * The whole argument should fit in a page to be able to pass to the hypervisor + * in one hypercall. + */ +#define HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES \ + ((HV_HYP_PAGE_SIZE - sizeof(struct hv_memory_hint)) / \ + sizeof(union hv_gpa_page_range)) + +/* HvExtCallMemoryHeatHint hypercall */ +#define HV_EXT_MEMORY_HEAT_HINT_TYPE_COLD_DISCARD 2 +struct hv_memory_hint { /* HV_EXT_INPUT_MEMORY_HEAT_HINT */ + u64 heat_type : 2; /* HV_EXTMEM_HEAT_HINT_* */ + u64 reserved : 62; + union hv_gpa_page_range ranges[]; +} __packed; + +#endif /* _HV_HVGDK_EXT_H */ -- cgit v1.3.1