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/sysctl.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 fs/ntfs/sysctl.c (limited to 'fs/ntfs/sysctl.c') diff --git a/fs/ntfs/sysctl.c b/fs/ntfs/sysctl.c new file mode 100644 index 000000000..8c5c1b7cd --- /dev/null +++ b/fs/ntfs/sysctl.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Code for sysctl handling in NTFS Linux kernel driver. + * + * Copyright (C) 1997 Martin von Löwis, Régis Duchesne + * Copyright (c) 2002-2005 Anton Altaparmakov + */ + +#ifdef DEBUG + +#include + +#ifdef CONFIG_SYSCTL + +#include +#include + +#include "sysctl.h" +#include "debug.h" + +/* Definition of the ntfs sysctl. */ +static const struct ctl_table ntfs_sysctls[] = { + { + .procname = "ntfs-debug", + .data = &debug_msgs, /* Data pointer and size. */ + .maxlen = sizeof(debug_msgs), + .mode = 0644, /* Mode, proc handler. */ + .proc_handler = proc_dointvec + }, +}; + +/* Storage for the sysctls header. */ +static struct ctl_table_header *sysctls_root_table; + +/* + * ntfs_sysctl - add or remove the debug sysctl + * @add: add (1) or remove (0) the sysctl + * + * Add or remove the debug sysctl. Return 0 on success or -errno on error. + */ +int ntfs_sysctl(int add) +{ + if (add) { + sysctls_root_table = register_sysctl("fs/ntfs", ntfs_sysctls); + if (!sysctls_root_table) + return -ENOMEM; + } else { + unregister_sysctl_table(sysctls_root_table); + sysctls_root_table = NULL; + } + return 0; +} +#endif /* CONFIG_SYSCTL */ +#endif /* DEBUG */ -- cgit v1.3.1