This is a note to let you know that I've just added the patch titled more bio_map_user_iov() leak fixes to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: more-bio_map_user_iov-leak-fixes.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 Mon Sep 17 00:00:00 2001 From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Date: Sat, 23 Sep 2017 15:51:23 -0400 Subject: more bio_map_user_iov() leak fixes From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> commit 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 upstream. we need to take care of failure exit as well - pages already in bio should be dropped by analogue of bio_unmap_pages(), since their refcounts had been bumped only once per reference in bio. Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/bio.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) --- a/block/bio.c +++ b/block/bio.c @@ -1266,6 +1266,7 @@ struct bio *bio_map_user_iov(struct requ int ret, offset; struct iov_iter i; struct iovec iov; + struct bio_vec *bvec; iov_for_each(iov, i, *iter) { unsigned long uaddr = (unsigned long) iov.iov_base; @@ -1310,7 +1311,12 @@ struct bio *bio_map_user_iov(struct requ ret = get_user_pages_fast(uaddr, local_nr_pages, (iter->type & WRITE) != WRITE, &pages[cur_page]); - if (ret < local_nr_pages) { + if (unlikely(ret < local_nr_pages)) { + for (j = cur_page; j < page_limit; j++) { + if (!pages[j]) + break; + put_page(pages[j]); + } ret = -EFAULT; goto out_unmap; } @@ -1372,10 +1378,8 @@ struct bio *bio_map_user_iov(struct requ return bio; out_unmap: - for (j = 0; j < nr_pages; j++) { - if (!pages[j]) - break; - put_page(pages[j]); + bio_for_each_segment_all(bvec, bio, j) { + put_page(bvec->bv_page); } out: kfree(pages); Patches currently in stable-queue which might be from viro@xxxxxxxxxxxxxxxxxx are queue-4.9/more-bio_map_user_iov-leak-fixes.patch queue-4.9/direct-io-prevent-null-pointer-access-in-submit_page_section.patch queue-4.9/bio_copy_user_iov-don-t-ignore-iov_offset.patch queue-4.9/fix-unbalanced-page-refcounting-in-bio_map_user_iov.patch