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[ Upstream commit 4cc871ad0173e8bc22f80e3609e34d546d30ef1a ]
The dc_data structure holds data required for handling compression
operations, such as overflow buffers. In this context, the use of
managed memory allocation APIs (devm_kzalloc() and devm_kfree())
is not necessary, as these data structures are freed and
re-allocated when a device is restarted in adf_dev_down() and
adf_dev_up().
Additionally, managed APIs automatically handle memory cleanup when the
device is detached, which can lead to conflicts with manual cleanup
processes. Specifically, if a device driver invokes the adf_dev_down()
function as part of the cleanup registered with
devm_add_action_or_reset(), it may attempt to free memory that is also
managed by the device's resource management system, potentially leading
to a double-free.
This might result in a warning similar to the following when unloading
the device specific driver, for example qat_6xxx.ko:
qat_free_dc_data+0x4f/0x60 [intel_qat]
qat_compression_event_handler+0x3d/0x1d0 [intel_qat]
adf_dev_shutdown+0x6d/0x1a0 [intel_qat]
adf_dev_down+0x32/0x50 [intel_qat]
devres_release_all+0xb8/0x110
device_unbind_cleanup+0xe/0x70
device_release_driver_internal+0x1c1/0x200
driver_detach+0x48/0x90
bus_remove_driver+0x74/0xf0
pci_unregister_driver+0x2e/0xb0
Use unmanaged memory allocation APIs (kzalloc_node() and kfree()) for
the dc_data structure. This ensures that memory is explicitly allocated
and freed under the control of the driver code, preventing manual
deallocation from interfering with automatic cleanup.
Fixes: 1198ae56c9 ("crypto: qat - expose deflate through acomp api for QAT GEN2")
Signed-off-by: Suman Kumar Chakraborty <suman.kumar.chakraborty@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.