6.6-stable review patch. If anyone has any objections, please let me know.
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From: Suman Kumar Chakraborty suman.kumar.chakraborty@intel.com
[ 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: 1198ae56c9a5 ("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 --- drivers/crypto/intel/qat/qat_common/qat_compression.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/crypto/intel/qat/qat_common/qat_compression.c b/drivers/crypto/intel/qat/qat_common/qat_compression.c index 7842a9f22178..2c3aa89b316a 100644 --- a/drivers/crypto/intel/qat/qat_common/qat_compression.c +++ b/drivers/crypto/intel/qat/qat_common/qat_compression.c @@ -197,7 +197,7 @@ static int qat_compression_alloc_dc_data(struct adf_accel_dev *accel_dev) struct adf_dc_data *dc_data = NULL; u8 *obuff = NULL;
- dc_data = devm_kzalloc(dev, sizeof(*dc_data), GFP_KERNEL); + dc_data = kzalloc_node(sizeof(*dc_data), GFP_KERNEL, dev_to_node(dev)); if (!dc_data) goto err;
@@ -235,7 +235,7 @@ static void qat_free_dc_data(struct adf_accel_dev *accel_dev) dma_unmap_single(dev, dc_data->ovf_buff_p, dc_data->ovf_buff_sz, DMA_FROM_DEVICE); kfree_sensitive(dc_data->ovf_buff); - devm_kfree(dev, dc_data); + kfree(dc_data); accel_dev->dc_data = NULL; }