From: Gabriel Krisman Bertazi krisman@suse.de
[ Upstream commit 67d1189d1095d471ed7fa426c7e384a7140a5dd7 ]
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 krisman@suse.de 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 axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- 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 25e2893320342..aabb367b24bc0 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2676,7 +2676,7 @@ 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;
@@ -2690,12 +2690,12 @@ 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]); @@ -2709,7 +2709,7 @@ static void *__io_uaddr_map(struct page ***pages, unsigned short *npages, * 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 @@ -2718,13 +2718,17 @@ static void *__io_uaddr_map(struct page ***pages, unsigned short *npages, * 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,