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/asm-generic/msi.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 include/asm-generic/msi.h (limited to 'include/asm-generic/msi.h') diff --git a/include/asm-generic/msi.h b/include/asm-generic/msi.h new file mode 100644 index 000000000..92cca4b23 --- /dev/null +++ b/include/asm-generic/msi.h @@ -0,0 +1,42 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_GENERIC_MSI_H +#define __ASM_GENERIC_MSI_H + +#include + +#ifdef CONFIG_GENERIC_MSI_IRQ + +#ifndef NUM_MSI_ALLOC_SCRATCHPAD_REGS +# define NUM_MSI_ALLOC_SCRATCHPAD_REGS 2 +#endif + +struct msi_desc; + +/** + * struct msi_alloc_info - Default structure for MSI interrupt allocation. + * @desc: Pointer to msi descriptor + * @hwirq: Associated hw interrupt number in the domain + * @scratchpad: Storage for implementation specific scratch data + * + * Architectures can provide their own implementation by not including + * asm-generic/msi.h into their arch specific header file. + */ +typedef struct msi_alloc_info { + struct msi_desc *desc; + irq_hw_number_t hwirq; + unsigned long flags; + union { + unsigned long ul; + void *ptr; + } scratchpad[NUM_MSI_ALLOC_SCRATCHPAD_REGS]; +} msi_alloc_info_t; + +/* Device generating MSIs is proxying for another device */ +#define MSI_ALLOC_FLAGS_PROXY_DEVICE (1UL << 0) +#define MSI_ALLOC_FLAGS_FIXED_MSG_DATA (1UL << 1) + +#define GENERIC_MSI_DOMAIN_OPS 1 + +#endif /* CONFIG_GENERIC_MSI_IRQ */ + +#endif -- cgit v1.3.1