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/dlm/util.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 fs/dlm/util.c (limited to 'fs/dlm/util.c') diff --git a/fs/dlm/util.c b/fs/dlm/util.c new file mode 100644 index 000000000..f2bc401f3 --- /dev/null +++ b/fs/dlm/util.c @@ -0,0 +1,66 @@ +// SPDX-License-Identifier: GPL-2.0-only +/****************************************************************************** +******************************************************************************* +** +** Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved. +** +** +******************************************************************************* +******************************************************************************/ + +#include "dlm_internal.h" +#include "rcom.h" +#include "util.h" + +#define DLM_ERRNO_EDEADLK 35 +#define DLM_ERRNO_EBADR 53 +#define DLM_ERRNO_EBADSLT 57 +#define DLM_ERRNO_EPROTO 71 +#define DLM_ERRNO_EOPNOTSUPP 95 +#define DLM_ERRNO_ETIMEDOUT 110 +#define DLM_ERRNO_EINPROGRESS 115 + +/* higher errno values are inconsistent across architectures, so select + one set of values for on the wire */ + +int to_dlm_errno(int err) +{ + switch (err) { + case -EDEADLK: + return -DLM_ERRNO_EDEADLK; + case -EBADR: + return -DLM_ERRNO_EBADR; + case -EBADSLT: + return -DLM_ERRNO_EBADSLT; + case -EPROTO: + return -DLM_ERRNO_EPROTO; + case -EOPNOTSUPP: + return -DLM_ERRNO_EOPNOTSUPP; + case -ETIMEDOUT: + return -DLM_ERRNO_ETIMEDOUT; + case -EINPROGRESS: + return -DLM_ERRNO_EINPROGRESS; + } + return err; +} + +int from_dlm_errno(int err) +{ + switch (err) { + case -DLM_ERRNO_EDEADLK: + return -EDEADLK; + case -DLM_ERRNO_EBADR: + return -EBADR; + case -DLM_ERRNO_EBADSLT: + return -EBADSLT; + case -DLM_ERRNO_EPROTO: + return -EPROTO; + case -DLM_ERRNO_EOPNOTSUPP: + return -EOPNOTSUPP; + case -DLM_ERRNO_ETIMEDOUT: + return -ETIMEDOUT; + case -DLM_ERRNO_EINPROGRESS: + return -EINPROGRESS; + } + return err; +} -- cgit v1.3.1