diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2020-04-08 07:58:46 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-04-08 17:26:51 +0200 |
| commit | 9c280f9087118099f50566e906b9d9d5a0fb4529 (patch) | |
| tree | d3554b855fc22b0c0caa3bf3ff478ebf2db90d27 /fs | |
| parent | io_uring: remove req init from io_get_req() (diff) | |
| download | linux-9c280f9087118099f50566e906b9d9d5a0fb4529.tar.xz linux-9c280f9087118099f50566e906b9d9d5a0fb4529.zip | |
io_uring: don't read user-shared sqe flags twice
Don't re-read userspace-shared sqe->flags, it can be exploited.
sqe->flags are copied into req->flags in io_submit_sqe(), check them
there instead.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io_uring.c | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 7f9bf8b6e6af..21e1c69b9c43 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2931,7 +2931,7 @@ static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (sqe->ioprio || sqe->buf_index) return -EINVAL; - if (sqe->flags & IOSQE_FIXED_FILE) + if (req->flags & REQ_F_FIXED_FILE) return -EBADF; if (req->flags & REQ_F_NEED_CLEANUP) return 0; @@ -2964,7 +2964,7 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (sqe->ioprio || sqe->buf_index) return -EINVAL; - if (sqe->flags & IOSQE_FIXED_FILE) + if (req->flags & REQ_F_FIXED_FILE) return -EBADF; if (req->flags & REQ_F_NEED_CLEANUP) return 0; @@ -3318,7 +3318,7 @@ static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (sqe->ioprio || sqe->buf_index) return -EINVAL; - if (sqe->flags & IOSQE_FIXED_FILE) + if (req->flags & REQ_F_FIXED_FILE) return -EBADF; if (req->flags & REQ_F_NEED_CLEANUP) return 0; @@ -3395,7 +3395,7 @@ static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (sqe->ioprio || sqe->off || sqe->addr || sqe->len || sqe->rw_flags || sqe->buf_index) return -EINVAL; - if (sqe->flags & IOSQE_FIXED_FILE) + if (req->flags & REQ_F_FIXED_FILE) return -EBADF; req->close.fd = READ_ONCE(sqe->fd); @@ -5366,15 +5366,10 @@ static int io_file_get(struct io_submit_state *state, struct io_kiocb *req, } static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req, - const struct io_uring_sqe *sqe) + int fd, unsigned int flags) { - unsigned flags; - int fd; bool fixed; - flags = READ_ONCE(sqe->flags); - fd = READ_ONCE(sqe->fd); - if (!io_req_needs_file(req, fd)) return 0; @@ -5616,7 +5611,7 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, { struct io_ring_ctx *ctx = req->ctx; unsigned int sqe_flags; - int ret, id; + int ret, id, fd; sqe_flags = READ_ONCE(sqe->flags); @@ -5647,7 +5642,8 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, IOSQE_ASYNC | IOSQE_FIXED_FILE | IOSQE_BUFFER_SELECT); - ret = io_req_set_file(state, req, sqe); + fd = READ_ONCE(sqe->fd); + ret = io_req_set_file(state, req, fd, sqe_flags); if (unlikely(ret)) { err_req: io_cqring_add_event(req, ret); |