From: Tang Yizhou tangyizhou@huawei.com
ascend inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4EUVI CVE: NA
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If vmap() or vmap_hugepage() fails in sp_make_share_u2k(), we need to decrease the reference count of the pages in struct sp_walk_data otherwise memleak happens.
There are also some additional cleanups to do.
Reported-by: Zhou Guanghui zhouguanghui1@huawei.com Signed-off-by: Tang Yizhou tangyizhou@huawei.com Reviewed-by: Ding Tianhong dingtianhong@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Reviewed-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- mm/share_pool.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/mm/share_pool.c b/mm/share_pool.c index 6cbbf2138ad6e..5149864c94c09 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -2019,6 +2019,22 @@ static int __sp_walk_page_range(unsigned long uva, unsigned long size, return ret; }
+static void __sp_walk_page_free(struct sp_walk_data *data) +{ + int i = 0; + struct page *page; + + while (i < data->page_count) { + page = data->pages[i++]; + put_page(page); + } + + kvfree(data->pages); + /* prevent repeated release */ + data->page_count = 0; + data->pages = NULL; +} + /** * Share user memory of a specified process to kernel * @uva: the VA of shared user memory @@ -2078,8 +2094,9 @@ void *sp_make_share_u2k(unsigned long uva, unsigned long size, int pid) if (!p) { if (printk_ratelimit()) pr_err("share pool: vmap(huge) in u2k failed\n"); + __sp_walk_page_free(&sp_walk_data); p = ERR_PTR(-ENOMEM); - goto out_free_pages; + goto out_put_task; } else { p = p + (uva - sp_walk_data.uva_aligned); } @@ -2092,7 +2109,6 @@ void *sp_make_share_u2k(unsigned long uva, unsigned long size, int pid) area = find_vm_area(p); area->flags |= VM_USERMAP;
-out_free_pages: kvfree(sp_walk_data.pages); out_put_task: put_task_struct(tsk); @@ -2393,20 +2409,12 @@ EXPORT_SYMBOL_GPL(sp_walk_page_range);
void sp_walk_page_free(struct sp_walk_data *sp_walk_data) { - struct page *page; - unsigned int i = 0; - check_interrupt_context();
if (!sp_walk_data) return;
- while (i < sp_walk_data->page_count) { - page = sp_walk_data->pages[i++]; - put_page(page); - } - - kvfree(sp_walk_data->pages); + __sp_walk_page_free(sp_walk_data); } EXPORT_SYMBOL_GPL(sp_walk_page_free);