From a05b82d5149dfeef05254a11c3636a89a854520a Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Fri, 21 Oct 2016 14:53:53 +0530 Subject: [PATCH] cxl: Fix leaking pid refs in some error paths In some error paths in functions cxl_start_context and afu_ioctl_start_work pid references to the current & group-leader tasks can leak after they are taken. This patch fixes these error paths to release these pid references before exiting the error path. Fixes: 7b8ad495d592 ("cxl: Fix DSI misses when the context owning task exits") Cc: stable@vger.kernel.org # v4.5+ Reviewed-by: Andrew Donnellan Reported-by: Frederic Barrat Signed-off-by: Vaibhav Jain Acked-by: Frederic Barrat Signed-off-by: Michael Ellerman --- drivers/misc/cxl/api.c | 2 ++ drivers/misc/cxl/file.c | 22 +++++++++++++--------- 2 files changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index af23d7dfe752..2e5233b60971 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -247,7 +247,9 @@ int cxl_start_context(struct cxl_context *ctx, u64 wed, cxl_ctx_get(); if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) { + put_pid(ctx->glpid); put_pid(ctx->pid); + ctx->glpid = ctx->pid = NULL; cxl_adapter_context_put(ctx->afu->adapter); cxl_ctx_put(); goto out; diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c index d0b421f49b39..77080cc5fa0a 100644 --- a/drivers/misc/cxl/file.c +++ b/drivers/misc/cxl/file.c @@ -193,6 +193,16 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF); + /* + * Increment the mapped context count for adapter. This also checks + * if adapter_context_lock is taken. + */ + rc = cxl_adapter_context_get(ctx->afu->adapter); + if (rc) { + afu_release_irqs(ctx, ctx); + goto out; + } + /* * We grab the PID here and not in the file open to allow for the case * where a process (master, some daemon, etc) has opened the chardev on @@ -205,15 +215,6 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, ctx->pid = get_task_pid(current, PIDTYPE_PID); ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID); - /* - * Increment the mapped context count for adapter. This also checks - * if adapter_context_lock is taken. - */ - rc = cxl_adapter_context_get(ctx->afu->adapter); - if (rc) { - afu_release_irqs(ctx, ctx); - goto out; - } trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr); @@ -221,6 +222,9 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, amr))) { afu_release_irqs(ctx, ctx); cxl_adapter_context_put(ctx->afu->adapter); + put_pid(ctx->glpid); + put_pid(ctx->pid); + ctx->glpid = ctx->pid = NULL; goto out; }