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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 , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Neal Cardwell , Kuniyuki Iwashima 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, netdev@vger.kernel.org, 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/OVpCdfQ3ZWMp9WSGLK+OWfJhtdL7uhLDRC0Ci/bcInJYkF8q6oQt8/+GWc51 JawqDN0lLIwiHEwyIopsgQF3zd4+XJdbbUbHzPMHFYmkCEMXJwCMJGt3xn+O8cetij4uVtU8oRf qCGz1BS7tZeaBNq/sjmlcTIZ/HKKY/hn2e/SwJmro3uEceW+PhXP5TmTz6kE/f4YvvhRyLEHv0W 5AA== X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 6A87EC0006 X-Stat-Signature: 9rokm8fabknymq4hq5qb6p8ctqmbsj69 X-Rspam-User: 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: 1794524092-155777 X-HE-Meta: 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 O3N6sITh swt/vEdyAqsdnKMzemvk4FkYYWHTVFmLyqTGP98GXOXUrcc4hMkaR3G2AaY3VBUJTCjQw1hV/18iT5ILxj8A2H52wMkg2VDXUtHYJgF3pST9eSkS/XpIbhmUeBGeym6yYvEiEuPWgKzhcG5vvpyKAQL4y207wOWcQUHbf5/e1D1awkVuN9Yx0Kl0g1m9l6hjqYudFGSc4ELI8WZ88G84k/Bg/C/qJuoALM1GOdtbDm75PbS5SURxjsQAnu3PuBsy/66zUeSF7cA15t5a2aHr5u/TZ2gjBXXSjRqUjnoJzjnU2YY7hjPzFbogXwTTk02i4tmg1t6+EKlimruaSedokCVSQjA== 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