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| author | Shivank Garg <shivankg@amd.com> | 2026-08-22 19:22:05 +0000 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2026-09-09 17:51:44 +0530 |
| commit | e873c74132f0c5f1452816cd9bb26208f0bba1e1 (patch) | |
| tree | cc1ce1567f5b982359331863ebd9da38741f8d2e /drivers/rtc/nvmem.c | |
| download | linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.tar.gz linux-stable-e873c74132f0c5f1452816cd9bb26208f0bba1e1.zip | |
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()grafted
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 <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/rtc/nvmem.c')
| -rw-r--r-- | drivers/rtc/nvmem.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/rtc/nvmem.c b/drivers/rtc/nvmem.c new file mode 100644 index 000000000..37df7e805 --- /dev/null +++ b/drivers/rtc/nvmem.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RTC subsystem, nvmem interface + * + * Copyright (C) 2017 Alexandre Belloni + */ + +#include <linux/err.h> +#include <linux/types.h> +#include <linux/nvmem-consumer.h> +#include <linux/rtc.h> + +int devm_rtc_nvmem_register(struct rtc_device *rtc, + struct nvmem_config *nvmem_config) +{ + struct device *dev = rtc->dev.parent; + struct nvmem_device *nvmem; + + if (!nvmem_config) + return -ENODEV; + + nvmem_config->dev = dev; + nvmem_config->owner = rtc->owner; + nvmem_config->add_legacy_fixed_of_cells = true; + nvmem = devm_nvmem_register(dev, nvmem_config); + if (IS_ERR(nvmem)) + dev_err(dev, "failed to register nvmem device for RTC\n"); + + return PTR_ERR_OR_ZERO(nvmem); +} +EXPORT_SYMBOL_GPL(devm_rtc_nvmem_register); |