Re: [PATCH] hugetlb: fix resv_map leak in error path
From: Christoph Lameter <hidden>
Date: 2012-05-22 21:05:08
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On Tue, 22 May 2012, Andrew Morton wrote:
On Mon, 21 May 2012 13:28:14 -0700 Dave Hansen [off-list ref] wrote:quoted
When called for anonymous (non-shared) mappings, hugetlb_reserve_pages() does a resv_map_alloc(). It depends on code in hugetlbfs's vm_ops->close() to release that allocation. However, in the mmap() failure path, we do a plain unmap_region() without the remove_vma() which actually calls vm_ops->close(). This is a decent fix. This leak could get reintroduced if new code (say, after hugetlb_reserve_pages() in hugetlbfs_file_mmap()) decides to return an error. But, I think it would have to unroll the reservation anyway.How far back does this bug go? The patch applies to 3.4 but gets rejects in 3.3 and earlier.
The earliest that I have seen it on was 2.6.32. I have rediffed the patch against 2.6.32 and 3.2.0. ----