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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , "Matthew Wilcox (Oracle)" , Jan Kara , Andrew Morton , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Matthew Brost , Joshua Hahn , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Peter Xu , Johannes Weiner , Song Liu , Rik van Riel , Miklos Szeredi , Alexander Viro , Christian Brauner , Hugh Dickins , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Arnd Bergmann , Jason Gunthorpe , Kevin Tian , "Joerg Roedel (AMD)" , Robin Murphy , Steve Sistare , John Hubbard , "Jose A. Perez de Azpillaga" , Josef Bacik Cc: "David Hildenbrand (Arm)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, fuse-devel@lists.linux.dev, linux-arch@vger.kernel.org, iommu@lists.linux.dev, stable@vger.kernel.org, Jason Gunthorpe X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3608; i=david@kernel.org; h=from:subject:message-id; bh=fau3pBzKpQXLjgKtqqi0yzExsXgD+rlECuO7Pn/e1yI=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLLeL2W0bHadVfTlfHZP64PqGzeK3Teah+fH6VZ+cpw0a 8b3bK2FHaUsDGIcDLJiiixBwfcNXr5cV1vtxscMM4eVCWQIAxenAEykZDkjw1KTmIgAwY894ov6 fFjzPUWdLKuu84grbV43U35iHm+dN8Mf7jCua4Zxe5lMu1PvLr2yifeOxIUA3UXyWnqt+rHOG/O 5AA== X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Stat-Signature: rnm79ne67gcqn51p4w3wjdzdcc7kxppj X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: EDE0F1A0007 X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-HE-Tag: 1794090302-337020 X-HE-Meta: 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 z5G/8Cdr aByQMKBKbWYDxwaluXH/pc9vJCfTjrWizT+JJG5ejMI09oSJLj8b1wDCB/CdJr9PWpm+QOuuCvr+lGTIvALQbcURpEdMu0w8cWnd25LCI3b008AnlgFPRkxdpmSpcTqalORo0uw9XrAYtm/3vPuebkRPvbDDwzGO1JfZ+gPa7EsAICcglQEHf2IrvtglfmpnBrabWKzp0rVY6r4+fU4ntEoSPq04fA25PowVkGfp6RPtDQ1Tx5hEvGjnO0ow0XCG3u2ETGIP/w1YSdRS24bmjp7GHpqUYv0Qp13FfJPXiXq+q2yulcP8unT0i0Rnf/b/6EJ6qfHn9JCCTaCgbS7EnDoS1Iw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 folio_add_pins() can fail after memfd_pin_folios() succeeded pinning a folio. Upcoming folio refcount limit checks will make this easier to trigger. Let's fix three problems in the error handling: 1. pfn_reader_release_pins() uses the allocated array size instead of the number of folios returned by memfd_pin_folios(). With large folios, cleanup can unpin uninitialized entries. Remember the number of returned folios and use that during cleanup. 2. pin_memfd_pages() returns on failure without releasing the pins acquired by the current call. Release the per-page pins for folios already expanded into the page array, and the single pins for the remaining folios. 3. pfn_reader_next() returns on failure before updating batch_end_index, even if the batch already contains successfully expanded folios. Update it before propagating the error so cleanup releases those pins as well. Fixes: 92687c793644 ("iommufd: pfn_reader for file mappings") Cc: stable@vger.kernel.org Reviewed-by: Lance Yang Reviewed-by: Jason Gunthorpe Signed-off-by: David Hildenbrand (Arm) --- drivers/iommu/iommufd/pages.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c index 2f6153108add7..fcdbde007a9ab 100644 --- a/drivers/iommu/iommufd/pages.c +++ b/drivers/iommu/iommufd/pages.c @@ -781,6 +781,7 @@ struct pfn_reader_user { struct file *file; struct folio **ufolios; size_t ufolios_len; + unsigned long ufolios_count; unsigned long ufolios_offset; struct folio **ufolios_next; }; @@ -800,6 +801,7 @@ static void pfn_reader_user_init(struct pfn_reader_user *user, user->file = (pages->type == IOPT_ADDRESS_FILE) ? pages->file : NULL; user->ufolios = NULL; user->ufolios_len = 0; + user->ufolios_count = 0; user->ufolios_next = NULL; user->ufolios_offset = 0; } @@ -843,6 +845,7 @@ static long pin_memfd_pages(struct pfn_reader_user *user, unsigned long start, offset >>= PAGE_SHIFT; user->ufolios_next = user->ufolios; + user->ufolios_count = nfolios; user->ufolios_offset = offset; for (i = 0; i < nfolios; i++) { @@ -859,8 +862,12 @@ static long pin_memfd_pages(struct pfn_reader_user *user, unsigned long start, } else { int rc = folio_add_pins(folio, npin - 1); - if (rc) + if (rc) { + unpin_user_pages(user->upages, + upages - user->upages); + unpin_folios(user->ufolios + i, nfolios - i); return rc; + } while (npin--) *upages++ = folio_page(folio, offset++); @@ -1251,14 +1258,14 @@ static int pfn_reader_next(struct pfn_reader *pfns) return -EINVAL; rc = pfn_reader_fill_span(pfns); + pfns->batch_end_index = pfns->batch_start_index + + pfns->batch.total_pfns; if (rc) return rc; if (WARN_ON(!pfns->batch.total_pfns)) return -EINVAL; - pfns->batch_end_index = - pfns->batch_start_index + pfns->batch.total_pfns; if (pfns->batch_end_index == pfns->span.last_used + 1) interval_tree_double_span_iter_next(&pfns->span); @@ -1320,7 +1327,7 @@ static void pfn_reader_release_pins(struct pfn_reader *pfns) if (!user->file) { unpin_user_pages(user->upages + start_index, npages); } else { - long n = user->ufolios_len / sizeof(*user->ufolios); + const unsigned long n = user->ufolios_count; unpin_folios(user->ufolios_next, user->ufolios + n - user->ufolios_next); -- 2.56.0