udmabuf: improve udmabuf_create error handling

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-9-kraxel@redhat.com

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index e32c381eca7d002b9c9c7fa08e78bc8b54361e0e..a3d225fd4d908ba9bbbe339e539e5882030d3fcf 100644 (file)
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -126,7 +126,7 @@ static long udmabuf_create(const struct udmabuf_create_list *head,
        struct file *memfd = NULL;
        struct udmabuf *ubuf;
        struct dma_buf *buf;
-       pgoff_t pgoff, pgcnt, pgidx, pgbuf, pglimit;
+       pgoff_t pgoff, pgcnt, pgidx, pgbuf = 0, pglimit;
        struct page *page;
        int seals, ret = -EINVAL;
        u32 i, flags;
@@ -138,32 +138,32 @@ static long udmabuf_create(const struct udmabuf_create_list *head,
        pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT;
        for (i = 0; i < head->count; i++) {
                if (!IS_ALIGNED(list[i].offset, PAGE_SIZE))
-                       goto err_free_ubuf;
+                       goto err;
                if (!IS_ALIGNED(list[i].size, PAGE_SIZE))
-                       goto err_free_ubuf;
+                       goto err;
                ubuf->pagecount += list[i].size >> PAGE_SHIFT;
                if (ubuf->pagecount > pglimit)
-                       goto err_free_ubuf;
+                       goto err;
        }
        ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(struct page *),
                                    GFP_KERNEL);
        if (!ubuf->pages) {
                ret = -ENOMEM;
-               goto err_free_ubuf;
+               goto err;
        }
 
        pgbuf = 0;
        for (i = 0; i < head->count; i++) {
                memfd = fget(list[i].memfd);
                if (!memfd)
-                       goto err_put_pages;
+                       goto err;
                if (!shmem_mapping(file_inode(memfd)->i_mapping))
-                       goto err_put_pages;
+                       goto err;
                seals = memfd_fcntl(memfd, F_GET_SEALS, 0);
                if (seals == -EINVAL ||
                    (seals & SEALS_WANTED) != SEALS_WANTED ||
                    (seals & SEALS_DENIED) != 0)
-                       goto err_put_pages;
+                       goto err;
                pgoff = list[i].offset >> PAGE_SHIFT;
                pgcnt = list[i].size   >> PAGE_SHIFT;
                for (pgidx = 0; pgidx < pgcnt; pgidx++) {
@@ -171,13 +171,13 @@ static long udmabuf_create(const struct udmabuf_create_list *head,
                                file_inode(memfd)->i_mapping, pgoff + pgidx);
                        if (IS_ERR(page)) {
                                ret = PTR_ERR(page);
-                               goto err_put_pages;
+                               goto err;
                        }
                        ubuf->pages[pgbuf++] = page;
                }
                fput(memfd);
+               memfd = NULL;
        }
-       memfd = NULL;
 
        exp_info.ops  = &udmabuf_ops;
        exp_info.size = ubuf->pagecount << PAGE_SHIFT;
@@ -186,7 +186,7 @@ static long udmabuf_create(const struct udmabuf_create_list *head,
        buf = dma_buf_export(&exp_info);
        if (IS_ERR(buf)) {
                ret = PTR_ERR(buf);
-               goto err_put_pages;
+               goto err;
        }
 
        flags = 0;
@@ -194,10 +194,9 @@ static long udmabuf_create(const struct udmabuf_create_list *head,
                flags |= O_CLOEXEC;
        return dma_buf_fd(buf, flags);
 
-err_put_pages:
+err:
        while (pgbuf > 0)
                put_page(ubuf->pages[--pgbuf]);
-err_free_ubuf:
        if (memfd)
                fput(memfd);
        kfree(ubuf->pages);