The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2b04e8f6bbb196cab4b232af0f8d48ff2c7a8058 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Date: Sat, 23 Sep 2017 15:51:23 -0400
Subject: [PATCH] more bio_map_user_iov() leak fixes
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.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
diff --git a/block/bio.c b/block/bio.c
index 0d6439e89acb..9e9606d26cc6 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1331,6 +1331,7 @@ struct bio *bio_map_user_iov(struct request_queue *q,
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;
@@ -1375,7 +1376,12 @@ struct bio *bio_map_user_iov(struct request_queue *q,
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;
}
@@ -1431,10 +1437,8 @@ struct bio *bio_map_user_iov(struct request_queue *q,
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);