From: Jens Axboe <axboe@kernel.dk> stable inclusion from stable-5.10.68 commit ce8f81b76d3bef7b9fe6c8f84d029ab898b19469 bugzilla: 182253 https://gitee.com/openeuler/kernel/issues/I4DDEL CVE: CVE-2021-41073 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc upstream. When setting up the next segment, we check what type the iter is and handle it accordingly. However, when incrementing and processed amount we do not, and both iter advance and addr/len are adjusted, regardless of type. Split the increment side just like we do on the setup side. Fixes: 4017eb91a9e7 ("io_uring: make loop_rw_iter() use original user supplied pointers") Cc: stable@vger.kernel.org Reported-by: Valentina Palmiotti <vpalmiotti@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Reviewed-by: Yang Erkun <yangerkun@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- fs/io_uring.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 108b0ed31c11..4361ed15e019 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3203,12 +3203,15 @@ static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter) ret = nr; break; } + if (!iov_iter_is_bvec(iter)) { + iov_iter_advance(iter, nr); + } else { + req->rw.len -= nr; + req->rw.addr += nr; + } ret += nr; if (nr != iovec.iov_len) break; - req->rw.len -= nr; - req->rw.addr += nr; - iov_iter_advance(iter, nr); } return ret; -- 2.20.1