4.19-stable review patch. If anyone has any objections, please let me know.
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From: Herbert Xu herbert@gondor.apana.org.au
commit d3b17c6d9dddc2db3670bc9be628b122416a3d26 upstream.
Using completion_done to determine whether the caller has gone away only works after a complete call. Furthermore it's still possible that the caller has not yet called wait_for_completion, resulting in another potential UAF.
Fix this by making the caller use cancel_work_sync and then freeing the memory safely.
Fixes: 7d42e097607c ("crypto: qat - resolve race condition during AER recovery") Cc: stable@vger.kernel.org #6.8+ Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Reviewed-by: Giovanni Cabiddu giovanni.cabiddu@intel.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/crypto/qat/qat_common/adf_aer.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-)
--- a/drivers/crypto/qat/qat_common/adf_aer.c +++ b/drivers/crypto/qat/qat_common/adf_aer.c @@ -139,8 +139,7 @@ static void adf_device_reset_worker(stru if (adf_dev_init(accel_dev) || adf_dev_start(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 || - completion_done(&reset_data->compl)) + if (reset_data->mode == ADF_DEV_RESET_ASYNC) kfree(reset_data); WARN(1, "QAT: device restart failed. Device is unusable\n"); return; @@ -148,16 +147,8 @@ static void adf_device_reset_worker(stru 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 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)) + /* The dev is back alive. Notify the caller if in sync mode */ + if (reset_data->mode == ADF_DEV_RESET_ASYNC) kfree(reset_data); else complete(&reset_data->compl); @@ -192,10 +183,10 @@ static int adf_dev_aer_schedule_reset(st if (!timeout) { dev_err(&GET_DEV(accel_dev), "Reset device timeout expired\n"); + cancel_work_sync(&reset_data->reset_work); ret = -EFAULT; - } else { - kfree(reset_data); } + kfree(reset_data); return ret; } return 0;