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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , "Matthew Wilcox (Oracle)" , Jan Kara , 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 , Hugh Dickins , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Jason Gunthorpe , Kevin Tian , "Joerg Roedel (AMD)" , Robin Murphy , Steve Sistare , John Hubbard Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, iommu@lists.linux.dev, "David Hildenbrand (Arm)" , stable@vger.kernel.org X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3513; i=david@kernel.org; h=from:subject:message-id; bh=xhwhJlBPehyF74AdW/XvbNaMmG2B0qFeGlvJE2A5afE=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLLeNFiGOoi/Tqjd2rLuo3LI1uLV80+ylDX63QtS+rj86 OueK6VRHaUsDGIcDLJiiixBwfcNXr5cV1vtxscMM4eVCWQIAxenAExE6DbDfz/rnLXTG9YuvdW2 v51td9KxD6+qG2787ev49NvQfrud2EmG//4fPNv0dn6R3P9i937u91PqfXfvuqq7qbV7yhZB1rP durwA X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Stat-Signature: omx67xx1yyo954qgnzfjrr37ji64fa39 X-Rspamd-Queue-Id: C79E3100006 X-Rspam-User: X-Rspamd-Server: rspam08 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: 1793884268-656502 X-HE-Meta: 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 ehErbzgn S05QmQ7b5pDLAhmy55i4LvfkUXQq3/QXe5tJbvYo9WCd5WoQxO2By9Zd+INNmpiLS+9KisAwxO/E9ts6u+twUJDc2VT7CpqizgSjIw3VpYwl1eISub6G5vAZP3Mdo/c+qY3eU/wpAcao2EziqH92O/lrrso8LLKvBSRR09643rssqLEh5PwgSzWYEROUIx3oRODLEmAaPSK0jfsnqqj707nUEZYm/ew6Glm8QNe0+6b2adlQ+4MQfEuskS695ZLawrPK/EwjF3SLyjtsYWR4L+LYmyimhOvsXirMDGP8FQpM9fQHpJRVlWzjJKu5DY1T3lmBP3TNgqPr+TioM7SiI8jdYzGd+Yo6+AxFO 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 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); -- 2.43.0