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 --- fs/9p/cache.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 fs/9p/cache.h (limited to 'fs/9p/cache.h') diff --git a/fs/9p/cache.h b/fs/9p/cache.h new file mode 100644 index 000000000..ee1b6b06a --- /dev/null +++ b/fs/9p/cache.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * V9FS cache definitions. + * + * Copyright (C) 2009 by Abhishek Kulkarni + */ + +#ifndef _9P_CACHE_H +#define _9P_CACHE_H + +#ifdef CONFIG_9P_FSCACHE +#include + +extern int v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses, + const char *dev_name); + +extern void v9fs_cache_inode_get_cookie(struct inode *inode); + +#else /* CONFIG_9P_FSCACHE */ + +static inline void v9fs_cache_inode_get_cookie(struct inode *inode) +{ +} + +#endif /* CONFIG_9P_FSCACHE */ +#endif /* _9P_CACHE_H */ -- cgit v1.3.1