diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2023-03-06 13:21:40 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 09:40:04 +0100 |
| commit | dde0d0dfbde23974d7449c04ef2fb8814d09deef (patch) | |
| tree | ab13f01005c6dacdcd5743e4d0b9b9231c6894b9 | |
| parent | abd54d87dabae7e50492f6ce1199a7ddadbbcaf8 (diff) | |
| download | linux-rt-dde0d0dfbde23974d7449c04ef2fb8814d09deef.tar.gz | |
io_uring/rsrc: disallow multi-source reg buffers
commit edd478269640b360c6f301f2baa04abdda563ef3 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | io_uring/io_uring.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 503a216b321b..acf4d49c7339 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -9228,14 +9228,17 @@ static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, 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; } |