Synchronize access to shm or shared memory buffer list to prevent race conditions due to concurrent updates to shared shm list by multiple threads.
Fixes: 757cc3e9ff1d ("tee: add AMD-TEE driver") Reviewed-by: Devaraj Rangasamy Devaraj.Rangasamy@amd.com Signed-off-by: Rijo Thomas Rijo-john.Thomas@amd.com --- drivers/tee/amdtee/amdtee_private.h | 1 + drivers/tee/amdtee/core.c | 8 ++++++++ 2 files changed, 9 insertions(+)
diff --git a/drivers/tee/amdtee/amdtee_private.h b/drivers/tee/amdtee/amdtee_private.h index 97df16a17285..337c8d82f74e 100644 --- a/drivers/tee/amdtee/amdtee_private.h +++ b/drivers/tee/amdtee/amdtee_private.h @@ -70,6 +70,7 @@ struct amdtee_session { struct amdtee_context_data { struct list_head sess_list; struct list_head shm_list; + struct mutex shm_mutex; /* synchronizes access to @shm_list */ };
struct amdtee_driver_data { diff --git a/drivers/tee/amdtee/core.c b/drivers/tee/amdtee/core.c index ce61c68ec58c..8a6a8f30bb42 100644 --- a/drivers/tee/amdtee/core.c +++ b/drivers/tee/amdtee/core.c @@ -42,6 +42,7 @@ static int amdtee_open(struct tee_context *ctx)
INIT_LIST_HEAD(&ctxdata->sess_list); INIT_LIST_HEAD(&ctxdata->shm_list); + mutex_init(&ctxdata->shm_mutex);
ctx->data = ctxdata; return 0; @@ -85,6 +86,7 @@ static void amdtee_release(struct tee_context *ctx) list_del(&sess->list_node); release_session(sess); } + mutex_destroy(&ctxdata->shm_mutex); kfree(ctxdata);
ctx->data = NULL; @@ -155,11 +157,13 @@ u32 get_buffer_id(struct tee_shm *shm) struct amdtee_shm_data *shmdata; u32 buf_id = 0;
+ mutex_lock(&ctxdata->shm_mutex); list_for_each_entry(shmdata, &ctxdata->shm_list, shm_node) if (shmdata->kaddr == shm->kaddr) { buf_id = shmdata->buf_id; break; } + mutex_unlock(&ctxdata->shm_mutex);
return buf_id; } @@ -364,7 +368,9 @@ int amdtee_map_shmem(struct tee_shm *shm) shmnode->kaddr = shm->kaddr; shmnode->buf_id = buf_id; ctxdata = shm->ctx->data; + mutex_lock(&ctxdata->shm_mutex); list_add(&shmnode->shm_node, &ctxdata->shm_list); + mutex_unlock(&ctxdata->shm_mutex);
pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
@@ -385,12 +391,14 @@ void amdtee_unmap_shmem(struct tee_shm *shm) handle_unmap_shmem(buf_id);
ctxdata = shm->ctx->data; + mutex_lock(&ctxdata->shm_mutex); list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node) if (buf_id == shmnode->buf_id) { list_del(&shmnode->shm_node); kfree(shmnode); break; } + mutex_unlock(&ctxdata->shm_mutex); }
int amdtee_invoke_func(struct tee_context *ctx,