Commit 75912905 authored Feb 09, 2024 by Damian Muszynski Committed by Aichun Shi Mar 26, 2024

crypto: qat - resolve race condition during AER recovery

mainline inclusion
from mainline-v6.9-rc1
commit 7d42e097607c4d246d99225bf2b195b6167a210c
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I9A5BW
CVE: N/A
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7d42e097607c4d246d99225bf2b195b6167a210c



-------------------------------------

During the PCI AER system's error recovery process, the kernel driver
may encounter a race condition with freeing the reset_data structure's
memory. If the device restart will take more than 10 seconds the function
scheduling that restart will exit due to a timeout, and the reset_data
structure will be freed. However, this data structure is used for
completion notification after the restart is completed, which leads
to a UAF bug.

This results in a KFENCE bug notice.

  BUG: KFENCE: use-after-free read in adf_device_reset_worker+0x38/0xa0 [intel_qat]
  Use-after-free read at 0x00000000bc56fddf (in kfence-#142):
  adf_device_reset_worker+0x38/0xa0 [intel_qat]
  process_one_work+0x173/0x340

To resolve this race condition, the memory associated to the container
of the work_struct is freed on the worker if the timeout expired,
otherwise on the function that schedules the worker.
The timeout detection can be done by checking if the caller is
still waiting for completion or not by using completion_done() function.

Intel-SIG: commit 7d42e097607c crypto: qat - resolve race condition during AER recovery
Backport to support QAT in-tree driver

Fixes: d8cba25d ("crypto: qat - Intel(R) QAT driver framework")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damian Muszynski <damian.muszynski@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[ Aichun Shi: amend commit log ]
Signed-off-by: Aichun Shi <aichun.shi@intel.com>

parent f9d1ac43

drivers/crypto/intel/qat/qat_common/adf_aer.c

+16 −6

Original line number	Diff line number	Diff line
		@@ -130,7 +130,8 @@ static void adf_device_reset_worker(struct work_struct *work)
		if (adf_dev_restart(accel_dev)) {
		/* The device hanged and we can't restart it so stop here */
		dev_err(&GET_DEV(accel_dev), "Restart device failed\n");
		if (reset_data->mode == ADF_DEV_RESET_ASYNC)
		if (reset_data->mode == ADF_DEV_RESET_ASYNC \|\|
		completion_done(&reset_data->compl))
		kfree(reset_data);
		WARN(1, "QAT: device restart failed. Device is unusable\n");
		return;
		@@ -146,11 +147,19 @@ static void adf_device_reset_worker(struct work_struct *work)
		adf_dev_restarted_notify(accel_dev);
		clear_bit(ADF_STATUS_RESTARTING, &accel_dev->status);

		/* The dev is back alive. Notify the caller if in sync mode */
		if (reset_data->mode == ADF_DEV_RESET_SYNC)
		complete(&reset_data->compl);
		else
		/*
		* The dev is back alive. Notify the caller if in sync mode
		*
		* If device restart will take a more time than expected,
		* the schedule_reset() function can timeout and exit. This can be
		* detected by calling the completion_done() function. In this case
		* the reset_data structure needs to be freed here.
		*/
		if (reset_data->mode == ADF_DEV_RESET_ASYNC \|\|
		completion_done(&reset_data->compl))
		kfree(reset_data);
		else
		complete(&reset_data->compl);
		}

		static int adf_dev_aer_schedule_reset(struct adf_accel_dev *accel_dev,
		@@ -183,8 +192,9 @@ static int adf_dev_aer_schedule_reset(struct adf_accel_dev *accel_dev,
		dev_err(&GET_DEV(accel_dev),
		"Reset device timeout expired\n");
		ret = -EFAULT;
		}
		} else {
		kfree(reset_data);
		}
		return ret;
		}
		return 0;