| From e5f1e1a343c5605385f67ddbb41633057aa3a4d4 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 15 Oct 2020 14:57:35 -0400 |
| Subject: sgl_alloc_order: fix memory leak |
| |
| From: Douglas Gilbert <dgilbert@interlog.com> |
| |
| [ Upstream commit b2a182a40278bc5849730e66bca01a762188ed86 ] |
| |
| sgl_alloc_order() can fail when 'length' is large on a memory |
| constrained system. When order > 0 it will potentially be |
| making several multi-page allocations with the later ones more |
| likely to fail than the earlier one. So it is important that |
| sgl_alloc_order() frees up any pages it has obtained before |
| returning NULL. In the case when order > 0 it calls the wrong |
| free page function and leaks. In testing the leak was |
| sufficient to bring down my 8 GiB laptop with OOM. |
| |
| Reviewed-by: Bart Van Assche <bvanassche@acm.org> |
| Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> |
| Signed-off-by: Jens Axboe <axboe@kernel.dk> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| lib/scatterlist.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/lib/scatterlist.c b/lib/scatterlist.c |
| index 5d63a8857f361..c448642e0f786 100644 |
| --- a/lib/scatterlist.c |
| +++ b/lib/scatterlist.c |
| @@ -514,7 +514,7 @@ struct scatterlist *sgl_alloc_order(unsigned long long length, |
| elem_len = min_t(u64, length, PAGE_SIZE << order); |
| page = alloc_pages(gfp, order); |
| if (!page) { |
| - sgl_free(sgl); |
| + sgl_free_order(sgl, order); |
| return NULL; |
| } |
| |
| -- |
| 2.27.0 |
| |
