diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 273919b16161..c2484551a4e8 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1568,6 +1568,7 @@ static ssize_t iov_iter_extract_xarray_pages(struct iov_iter *i, struct folio *folio; unsigned int nr = 0, offset; loff_t pos = i->xarray_start + i->iov_offset; + bool will_alloc = !*pages; XA_STATE(xas, i->xarray, pos >> PAGE_SHIFT); offset = pos & ~PAGE_MASK; @@ -1595,6 +1596,14 @@ static ssize_t iov_iter_extract_xarray_pages(struct iov_iter *i, } rcu_read_unlock(); + if (!nr) { + if (will_alloc) { + kvfree(*pages); + *pages = NULL; + } + return 0; + } + maxsize = min_t(size_t, nr * PAGE_SIZE - offset, maxsize); iov_iter_advance(i, maxsize); return maxsize; @@ -1628,6 +1637,8 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i, bi.bi_bvec_done = skip; maxpages = want_pages_array(pages, maxsize, skip, maxpages); + if (!maxpages) + return -ENOMEM; while (bi.bi_size && bi.bi_idx < i->nr_segs) { struct bio_vec bv = bvec_iter_bvec(i->bvec, bi); @@ -1745,6 +1756,7 @@ static ssize_t iov_iter_extract_user_pages(struct iov_iter *i, unsigned long addr; unsigned int gup_flags = 0; size_t offset; + bool will_alloc = !*pages; int res; if (i->data_source == ITER_DEST) @@ -1761,8 +1773,14 @@ static ssize_t iov_iter_extract_user_pages(struct iov_iter *i, if (!maxpages) return -ENOMEM; res = pin_user_pages_fast(addr, maxpages, gup_flags, *pages); - if (unlikely(res <= 0)) + if (unlikely(res <= 0)) { + if (will_alloc) { + kvfree(*pages); + *pages = NULL; + } return res; + } + maxsize = min_t(size_t, maxsize, res * PAGE_SIZE - offset); iov_iter_advance(i, maxsize); return maxsize; |