staging: vme_user: Fix possible UAF in tsi148_dma_list_add

[ Upstream commit 357057e ]

Smatch report warning as follows:

drivers/staging/vme_user/vme_tsi148.c:1757 tsi148_dma_list_add() warn:
  '&entry->list' not removed from list

In tsi148_dma_list_add(), the error path "goto err_dma" will not
remove entry->list from list->entries, but entry will be freed,
then list traversal may cause UAF.

Fix by removeing it from list->entries before free().

Fixes: b2383c9 ("vme: tsi148: fix first DMA item mapping")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221117035914.2954454-1-cuigaosheng1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/staging/vme_user/vme_tsi148.c

@@ -1751,6 +1751,7 @@ static int tsi148_dma_list_add(struct vme_dma_list *list,
 	return 0;
 
 err_dma:
+	list_del(&entry->list);
 err_dest:
 err_source:
 err_align: