The amdgpu_cs_parser_init() function doesn't clean up after itself but instead the caller uses a free everything function amdgpu_cs_parser_fini() on failure. This style of error handling is often buggy. In this example, we call "drm_free_large(parser->chunks[i].kdata);" when it is an unintialized pointer or when "parser->chunks" is NULL.
I fixed this bug by adding unwind code so that it frees everything that it allocates.
I also mode some other very minor changes: 1) Renamed "r" to "ret". 2) Moved the chunk_array allocation to the start of the function. 3) Removed some initializers which are no longer needed.
Reported-by: Ilja Van Sprundel ivansprundel@ioactive.com Signed-off-by: Dan Carpenter dan.carpenter@oracle.com
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 3b355ae..abb257d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -154,42 +154,41 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) { union drm_amdgpu_cs *cs = data; uint64_t *chunk_array_user; - uint64_t *chunk_array = NULL; + uint64_t *chunk_array; struct amdgpu_fpriv *fpriv = p->filp->driver_priv; unsigned size, i; - int r = 0; + int ret;
- if (!cs->in.num_chunks) - goto out; + if (cs->in.num_chunks == 0) + return 0; + + chunk_array = kmalloc_array(cs->in.num_chunks, sizeof(uint64_t), GFP_KERNEL); + if (!chunk_array) + return -ENOMEM;
p->ctx = amdgpu_ctx_get(fpriv, cs->in.ctx_id); if (!p->ctx) { - r = -EINVAL; - goto out; + ret = -EINVAL; + goto free_chunk; } + p->bo_list = amdgpu_bo_list_get(fpriv, cs->in.bo_list_handle);
/* get chunks */ INIT_LIST_HEAD(&p->validated); - chunk_array = kmalloc_array(cs->in.num_chunks, sizeof(uint64_t), GFP_KERNEL); - if (chunk_array == NULL) { - r = -ENOMEM; - goto out; - } - chunk_array_user = (uint64_t __user *)(cs->in.chunks); if (copy_from_user(chunk_array, chunk_array_user, sizeof(uint64_t)*cs->in.num_chunks)) { - r = -EFAULT; - goto out; + ret = -EFAULT; + goto put_bo_list; }
p->nchunks = cs->in.num_chunks; p->chunks = kmalloc_array(p->nchunks, sizeof(struct amdgpu_cs_chunk), GFP_KERNEL); - if (p->chunks == NULL) { - r = -ENOMEM; - goto out; + if (!p->chunks) { + ret = -ENOMEM; + goto put_bo_list; }
for (i = 0; i < p->nchunks; i++) { @@ -200,8 +199,9 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) chunk_ptr = (void __user *)chunk_array[i]; if (copy_from_user(&user_chunk, chunk_ptr, sizeof(struct drm_amdgpu_cs_chunk))) { - r = -EFAULT; - goto out; + ret = -EFAULT; + i--; + goto free_partial_kdata; } p->chunks[i].chunk_id = user_chunk.chunk_id; p->chunks[i].length_dw = user_chunk.length_dw; @@ -212,13 +212,14 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
p->chunks[i].kdata = drm_malloc_ab(size, sizeof(uint32_t)); if (p->chunks[i].kdata == NULL) { - r = -ENOMEM; - goto out; + ret = -ENOMEM; + i--; + goto free_partial_kdata; } size *= sizeof(uint32_t); if (copy_from_user(p->chunks[i].kdata, cdata, size)) { - r = -EFAULT; - goto out; + ret = -EFAULT; + goto free_partial_kdata; }
switch (p->chunks[i].chunk_id) { @@ -238,15 +239,15 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) gobj = drm_gem_object_lookup(p->adev->ddev, p->filp, handle); if (gobj == NULL) { - r = -EINVAL; - goto out; + ret = -EINVAL; + goto free_partial_kdata; }
p->uf.bo = gem_to_amdgpu_bo(gobj); p->uf.offset = fence_data->offset; } else { - r = -EINVAL; - goto out; + ret = -EINVAL; + goto free_partial_kdata; } break;
@@ -254,19 +255,35 @@ int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data) break;
default: - r = -EINVAL; - goto out; + ret = -EINVAL; + goto free_partial_kdata; } }
p->ibs = kcalloc(p->num_ibs, sizeof(struct amdgpu_ib), GFP_KERNEL); - if (!p->ibs) - r = -ENOMEM; + if (!p->ibs) { + ret = -ENOMEM; + goto free_all_kdata; + }
-out: kfree(chunk_array); - return r; + return 0; + +free_all_kdata: + i = p->nchunks - 1; +free_partial_kdata: + for (; i >= 0; i--) + drm_free_large(p->chunks[i].kdata); + kfree(p->chunks); +put_bo_list: + if (p->bo_list) + amdgpu_bo_list_put(p->bo_list); + amdgpu_ctx_put(p->ctx); +free_chunk: + kfree(chunk_array); + + return ret; }
/* Returns how many bytes TTM can move per IB. @@ -804,7 +821,7 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp) r = amdgpu_cs_parser_init(parser, data); if (r) { DRM_ERROR("Failed to initialize parser !\n"); - amdgpu_cs_parser_fini(parser, r, false); + kfree(parser); up_read(&adev->exclusive_lock); r = amdgpu_cs_handle_lockup(adev, r); return r;