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authorPavel Begunkov <asml.silence@gmail.com>2020-04-08 08:58:46 +0300
committerJens Axboe <axboe@kernel.dk>2020-04-08 09:26:51 -0600
commit9c280f9087118099f50566e906b9d9d5a0fb4529 (patch)
treed3554b855fc22b0c0caa3bf3ff478ebf2db90d27 /fs
parent0553b8bda8709c47863eab3fff7ac32ad04ca52b (diff)
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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.c20
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);