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/ntfs/malloc.h | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 fs/ntfs/malloc.h (limited to 'fs/ntfs/malloc.h') diff --git a/fs/ntfs/malloc.h b/fs/ntfs/malloc.h new file mode 100644 index 000000000..706842573 --- /dev/null +++ b/fs/ntfs/malloc.h @@ -0,0 +1,77 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * malloc.h - NTFS kernel memory handling. Part of the Linux-NTFS project. + * + * Copyright (c) 2001-2005 Anton Altaparmakov + */ + +#ifndef _LINUX_NTFS_MALLOC_H +#define _LINUX_NTFS_MALLOC_H + +#include +#include +#include + +/** + * __ntfs_malloc - allocate memory in multiples of pages + * @size: number of bytes to allocate + * @gfp_mask: extra flags for the allocator + * + * Internal function. You probably want ntfs_malloc_nofs()... + * + * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and + * returns a pointer to the allocated memory. + * + * If there was insufficient memory to complete the request, return NULL. + * Depending on @gfp_mask the allocation may be guaranteed to succeed. + */ +static inline void *__ntfs_malloc(unsigned long size, gfp_t gfp_mask) +{ + if (likely(size <= PAGE_SIZE)) { + BUG_ON(!size); + /* kmalloc() has per-CPU caches so is faster for now. */ + return kmalloc(PAGE_SIZE, gfp_mask & ~__GFP_HIGHMEM); + /* return (void *)__get_free_page(gfp_mask); */ + } + if (likely((size >> PAGE_SHIFT) < totalram_pages())) + return __vmalloc(size, gfp_mask); + return NULL; +} + +/** + * ntfs_malloc_nofs - allocate memory in multiples of pages + * @size: number of bytes to allocate + * + * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and + * returns a pointer to the allocated memory. + * + * If there was insufficient memory to complete the request, return NULL. + */ +static inline void *ntfs_malloc_nofs(unsigned long size) +{ + return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM); +} + +/** + * ntfs_malloc_nofs_nofail - allocate memory in multiples of pages + * @size: number of bytes to allocate + * + * Allocates @size bytes of memory, rounded up to multiples of PAGE_SIZE and + * returns a pointer to the allocated memory. + * + * This function guarantees that the allocation will succeed. It will sleep + * for as long as it takes to complete the allocation. + * + * If there was insufficient memory to complete the request, return NULL. + */ +static inline void *ntfs_malloc_nofs_nofail(unsigned long size) +{ + return __ntfs_malloc(size, GFP_NOFS | __GFP_HIGHMEM | __GFP_NOFAIL); +} + +static inline void ntfs_free(void *addr) +{ + kvfree(addr); +} + +#endif /* _LINUX_NTFS_MALLOC_H */ -- cgit v1.3.1