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/sysfs/sysfs.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 fs/sysfs/sysfs.h (limited to 'fs/sysfs/sysfs.h') diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h new file mode 100644 index 000000000..f4583dcaf --- /dev/null +++ b/fs/sysfs/sysfs.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * fs/sysfs/sysfs.h - sysfs internal header file + * + * Copyright (c) 2001-3 Patrick Mochel + * Copyright (c) 2007 SUSE Linux Products GmbH + * Copyright (c) 2007 Tejun Heo + */ + +#ifndef __SYSFS_INTERNAL_H +#define __SYSFS_INTERNAL_H + +#include + +/* + * mount.c + */ +extern struct kernfs_node *sysfs_root_kn; + +/* + * dir.c + */ +extern spinlock_t sysfs_symlink_target_lock; + +void sysfs_warn_dup(struct kernfs_node *parent, const char *name); + +/* + * file.c + */ +int sysfs_add_file_mode_ns(struct kernfs_node *parent, + const struct attribute *attr, umode_t amode, kuid_t uid, + kgid_t gid, const struct ns_common *ns); +int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent, + const struct bin_attribute *battr, umode_t mode, size_t size, + kuid_t uid, kgid_t gid, const struct ns_common *ns); + +/* + * symlink.c + */ +int sysfs_create_link_sd(struct kernfs_node *kn, struct kobject *target, + const char *name); + +#endif /* __SYSFS_INTERNAL_H */ -- cgit v1.3.1