On Mon, Apr 8, 2019 at 11:10 AM Chia-I Wu <olva...@gmail.com> wrote:
>
>
>
> On Mon, Apr 8, 2019 at 9:34 AM Lepton Wu <lep...@chromium.org> wrote:
>>
>> The old code could use gem name as key when inserting it to bo_handles
>> hash table while trying to remove it from hash table with bo_handle as
>> key in virgl_hw_res_destroy and then it fail to remove it from bo_handles
>> hash table. This triggers use after free. Also, we should insert resource
>> to bo_names hash table when handle type is SHARED.
>>
>> Signed-off-by: Lepton Wu <lep...@chromium.org>
>> ---
>> .../winsys/virgl/drm/virgl_drm_winsys.c | 24 +++++++++++++------
>> 1 file changed, 17 insertions(+), 7 deletions(-)
>>
>> diff --git a/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
>> b/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
>> index 2cf8b4ba076..af92b6a98fc 100644
>> --- a/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
>> +++ b/src/gallium/winsys/virgl/drm/virgl_drm_winsys.c
>> @@ -406,6 +406,12 @@ virgl_drm_winsys_resource_create_handle(struct
>> virgl_winsys *qws,
>> return NULL;
>> }
>>
>> + if (whandle->type != WINSYS_HANDLE_TYPE_FD &&
>> + whandle->type != WINSYS_HANDLE_TYPE_SHARED) {
>> + fprintf(stderr, "Unexpected handle type: %d\n", whandle->type);
>> + return NULL;
>> + }
>> +
>> mtx_lock(&qdws->bo_handles_mutex);
>>
>> if (whandle->type == WINSYS_HANDLE_TYPE_SHARED) {
>> @@ -424,13 +430,13 @@ virgl_drm_winsys_resource_create_handle(struct
>> virgl_winsys *qws,
>> res = NULL;
>> goto done;
>> }
>> - }
>>
>> - res = util_hash_table_get(qdws->bo_handles, (void*)(uintptr_t)handle);
>> - if (res) {
>> - struct virgl_hw_res *r = NULL;
>> - virgl_drm_resource_reference(qdws, &r, res);
>> - goto done;
>> + res = util_hash_table_get(qdws->bo_handles, (void*)(uintptr_t)handle);
>> + if (res) {
>> + struct virgl_hw_res *r = NULL;
>> + virgl_drm_resource_reference(qdws, &r, res);
>> + goto done;
>> + }
>> }
>>
> You can still run into troubles when asked to import a buffer by both its
> prime fd and its flink name.
But it seems there is no way to fix it at user space, right? Every
time we got a flink name for
the first time, kernel will give a new handle and no way to reuse any
res from hash table.
>
>> res = CALLOC_STRUCT(virgl_hw_res);
>> @@ -448,6 +454,8 @@ virgl_drm_winsys_resource_create_handle(struct
>> virgl_winsys *qws,
>> goto done;
>> }
>> res->bo_handle = open_arg.handle;
>> + res->flinked = true;
>> + res->flink = whandle->handle;
>> }
>> res->name = handle;
>
> res->name has no user. Remove it.
>
> It is also less confusing to make sure `handle' means GEM handle at this
> point, by calling either GEM_OPEN or drmPrimeFDToHandle depending on the
> handle type.
>
>>
>> @@ -469,7 +477,9 @@ virgl_drm_winsys_resource_create_handle(struct
>> virgl_winsys *qws,
>> res->num_cs_references = 0;
>> res->fence_fd = -1;
>>
>> - util_hash_table_set(qdws->bo_handles, (void *)(uintptr_t)handle, res);
>> + util_hash_table_set(qdws->bo_handles, (void *)(uintptr_t)res->bo_handle,
>> res);
>> + if (whandle->type == WINSYS_HANDLE_TYPE_SHARED)
>> + util_hash_table_set(qdws->bo_names, (void *)(uintptr_t)res->flink,
>> res);
>>
>> done:
>> mtx_unlock(&qdws->bo_handles_mutex);
>> --
>> 2.21.0.392.gf8f6787159e-goog
>>
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