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 --- drivers/firmware/google/memconsole.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 drivers/firmware/google/memconsole.h (limited to 'drivers/firmware/google/memconsole.h') diff --git a/drivers/firmware/google/memconsole.h b/drivers/firmware/google/memconsole.h new file mode 100644 index 000000000..aaff2b72b --- /dev/null +++ b/drivers/firmware/google/memconsole.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * memconsole.h + * + * Internal headers of the memory based BIOS console. + * + * Copyright 2017 Google Inc. + */ + +#ifndef __FIRMWARE_GOOGLE_MEMCONSOLE_H +#define __FIRMWARE_GOOGLE_MEMCONSOLE_H + +#include + +/* + * memconsole_setup + * + * Initialize the memory console, passing the function to handle read accesses. + */ +void memconsole_setup(ssize_t (*read_func)(char *, loff_t, size_t)); + +/* + * memconsole_sysfs_init + * + * Update memory console length and create binary file + * for firmware object. + */ +int memconsole_sysfs_init(void); + +/* memconsole_exit + * + * Unmap the console buffer. + */ +void memconsole_exit(void); + +#endif /* __FIRMWARE_GOOGLE_MEMCONSOLE_H */ -- cgit v1.3.1