From: Mikulas Patocka <mpatocka@redhat.com> stable inclusion from stable-v6.6.3 commit 0b1f2f895470a4a663b471054ba25ce88ba86d09 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 9793c269da6cd339757de6ba5b2c8681b54c99af upstream. The commit 5054e778fcd9c ("dm crypt: allocate compound pages if possible") changed dm-crypt to use compound pages to improve performance. Unfortunately, there was an oversight: the allocation of compound pages was not accounted at all. Normal pages are accounted in a percpu counter cc->n_allocated_pages and dm-crypt is limited to allocate at most 2% of memory. Because compound pages were not accounted at all, dm-crypt could allocate memory over the 2% limit. Fix this by adding the accounting of compound pages, so that memory consumption of dm-crypt is properly limited. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 5054e778fcd9c ("dm crypt: allocate compound pages if possible") Cc: stable@vger.kernel.org # v6.5+ Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/md/dm-crypt.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 5315fd261c23..cef9353370b2 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1699,11 +1699,17 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size) order = min(order, remaining_order); while (order > 0) { + if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) + + (1 << order) > dm_crypt_pages_per_client)) + goto decrease_order; pages = alloc_pages(gfp_mask | __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP, order); - if (likely(pages != NULL)) + if (likely(pages != NULL)) { + percpu_counter_add(&cc->n_allocated_pages, 1 << order); goto have_pages; + } +decrease_order: order--; } @@ -1741,10 +1747,13 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */ bio_for_each_folio_all(fi, clone) { - if (folio_test_large(fi.folio)) + if (folio_test_large(fi.folio)) { + percpu_counter_sub(&cc->n_allocated_pages, + 1 << folio_order(fi.folio)); folio_put(fi.folio); - else + } else { mempool_free(&fi.folio->page, &cc->page_pool); + } } } } -- 2.25.1