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/uapi/asm-generic/stat.h | 73 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 include/uapi/asm-generic/stat.h (limited to 'include/uapi/asm-generic/stat.h') diff --git a/include/uapi/asm-generic/stat.h b/include/uapi/asm-generic/stat.h new file mode 100644 index 000000000..0d962ecd1 --- /dev/null +++ b/include/uapi/asm-generic/stat.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __ASM_GENERIC_STAT_H +#define __ASM_GENERIC_STAT_H + +/* + * Everybody gets this wrong and has to stick with it for all + * eternity. Hopefully, this version gets used by new architectures + * so they don't fall into the same traps. + * + * stat64 is copied from powerpc64, with explicit padding added. + * stat is the same structure layout on 64-bit, without the 'long long' + * types. + * + * By convention, 64 bit architectures use the stat interface, while + * 32 bit architectures use the stat64 interface. Note that we don't + * provide an __old_kernel_stat here, which new architecture should + * not have to start with. + */ + +#include + +#define STAT_HAVE_NSEC 1 + +struct stat { + unsigned long st_dev; /* Device. */ + unsigned long st_ino; /* File serial number. */ + unsigned int st_mode; /* File mode. */ + unsigned int st_nlink; /* Link count. */ + unsigned int st_uid; /* User ID of the file's owner. */ + unsigned int st_gid; /* Group ID of the file's group. */ + unsigned long st_rdev; /* Device number, if device. */ + unsigned long __pad1; + long st_size; /* Size of file, in bytes. */ + int st_blksize; /* Optimal block size for I/O. */ + int __pad2; + long st_blocks; /* Number 512-byte blocks allocated. */ + long st_atime; /* Time of last access. */ + unsigned long st_atime_nsec; + long st_mtime; /* Time of last modification. */ + unsigned long st_mtime_nsec; + long st_ctime; /* Time of last status change. */ + unsigned long st_ctime_nsec; + unsigned int __unused4; + unsigned int __unused5; +}; + +/* This matches struct stat64 in glibc2.1. Only used for 32 bit. */ +#if __BITS_PER_LONG != 64 || defined(__ARCH_WANT_STAT64) +struct stat64 { + unsigned long long st_dev; /* Device. */ + unsigned long long st_ino; /* File serial number. */ + unsigned int st_mode; /* File mode. */ + unsigned int st_nlink; /* Link count. */ + unsigned int st_uid; /* User ID of the file's owner. */ + unsigned int st_gid; /* Group ID of the file's group. */ + unsigned long long st_rdev; /* Device number, if device. */ + unsigned long long __pad1; + long long st_size; /* Size of file, in bytes. */ + int st_blksize; /* Optimal block size for I/O. */ + int __pad2; + long long st_blocks; /* Number 512-byte blocks allocated. */ + int st_atime; /* Time of last access. */ + unsigned int st_atime_nsec; + int st_mtime; /* Time of last modification. */ + unsigned int st_mtime_nsec; + int st_ctime; /* Time of last status change. */ + unsigned int st_ctime_nsec; + unsigned int __unused4; + unsigned int __unused5; +}; +#endif + +#endif /* __ASM_GENERIC_STAT_H */ -- cgit v1.3.1