diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2023-02-22 14:36:48 +0000 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-02-22 09:57:23 -0700 |
| commit | edd478269640b360c6f301f2baa04abdda563ef3 (patch) | |
| tree | 1c08693236b6949304de804e818b88f77dab99c8 /io_uring | |
| parent | 9a1563d1720680bdc1d702486b7b73f51c079b32 (diff) | |
io_uring/rsrc: disallow multi-source reg buffers
If two or more mappings go back to back to each other they can be passed
into io_uring to be registered as a single registered buffer. That would
even work if mappings came from different sources, e.g. it's possible to
mix in this way anon pages and pages from shmem or hugetlb. That is not
a problem but it'd rather be less prone if we forbid such mixing.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/rsrc.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 4e6191904c9e..53845e496881 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -1162,14 +1162,17 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages) pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, pages, vmas); if (pret == nr_pages) { + struct file *file = vmas[0]->vm_file; + /* don't support file backed memory */ for (i = 0; i < nr_pages; i++) { - struct vm_area_struct *vma = vmas[i]; - - if (vma_is_shmem(vma)) + if (vmas[i]->vm_file != file) { + ret = -EINVAL; + break; + } + if (!file) continue; - if (vma->vm_file && - !is_file_hugepages(vma->vm_file)) { + if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) { ret = -EOPNOTSUPP; break; } |