From 67d1189d1095d471ed7fa426c7e384a7140a5dd7 Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Wed, 13 Mar 2024 17:39:12 -0400 Subject: [PATCH] io_uring: Fix release of pinned pages when __io_uaddr_map fails Looking at the error path of __io_uaddr_map, if we fail after pinning the pages for any reasons, ret will be set to -EINVAL and the error handler won't properly release the pinned pages. I didn't manage to trigger it without forcing a failure, but it can happen in real life when memory is heavily fragmented. Signed-off-by: Gabriel Krisman Bertazi Fixes: 223ef4743164 ("io_uring: don't allow IORING_SETUP_NO_MMAP rings on highmem pages") Link: https://lore.kernel.org/r/20240313213912.1920-1-krisman@suse.de Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 48c8d74e86ab..3ae4bb988906 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2714,7 +2714,7 @@ static void *__io_uaddr_map(struct page ***pages, unsigned short *npages, struct page **page_array; unsigned int nr_pages; void *page_addr; - int ret, i; + int ret, i, pinned; *npages = 0; @@ -2728,12 +2728,12 @@ static void *__io_uaddr_map(struct page ***pages, unsigned short *npages, if (!page_array) return ERR_PTR(-ENOMEM); - ret = pin_user_pages_fast(uaddr, nr_pages, FOLL_WRITE | FOLL_LONGTERM, - page_array); - if (ret != nr_pages) { -err: - io_pages_free(&page_array, ret > 0 ? ret : 0); - return ret < 0 ? ERR_PTR(ret) : ERR_PTR(-EFAULT); + + pinned = pin_user_pages_fast(uaddr, nr_pages, FOLL_WRITE | FOLL_LONGTERM, + page_array); + if (pinned != nr_pages) { + ret = (pinned < 0) ? pinned : -EFAULT; + goto free_pages; } page_addr = page_address(page_array[0]); @@ -2747,7 +2747,7 @@ err: * didn't support this feature. */ if (PageHighMem(page_array[i])) - goto err; + goto free_pages; /* * No support for discontig pages for now, should either be a @@ -2756,13 +2756,17 @@ err: * just fail them with EINVAL. */ if (page_address(page_array[i]) != page_addr) - goto err; + goto free_pages; page_addr += PAGE_SIZE; } *pages = page_array; *npages = nr_pages; return page_to_virt(page_array[0]); + +free_pages: + io_pages_free(&page_array, pinned > 0 ? pinned : 0); + return ERR_PTR(ret); } static void *io_rings_map(struct io_ring_ctx *ctx, unsigned long uaddr,