[PATCH 2/2] io_uring: fix openat/statx's filename leak

From: Pavel Begunkov
Date: Sat Feb 08 2020 - 05:29:11 EST


As in the previous patch, make openat*_prep() and statx_prep() to
handle double prepartion to avoid resource leakage.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index f5aa2fdccf7a..c3bac9d850a5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2536,6 +2536,8 @@ static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return -EINVAL;
if (sqe->flags & IOSQE_FIXED_FILE)
return -EINVAL;
+ if (req->flags & REQ_F_NEED_CLEANUP)
+ return 0;

req->open.dfd = READ_ONCE(sqe->fd);
req->open.how.mode = READ_ONCE(sqe->len);
@@ -2564,6 +2566,8 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return -EINVAL;
if (sqe->flags & IOSQE_FIXED_FILE)
return -EINVAL;
+ if (req->flags & REQ_F_NEED_CLEANUP)
+ return 0;

req->open.dfd = READ_ONCE(sqe->fd);
fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -2763,6 +2767,8 @@ static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return -EINVAL;
if (sqe->flags & IOSQE_FIXED_FILE)
return -EINVAL;
+ if (req->flags & REQ_F_NEED_CLEANUP)
+ return 0;

req->open.dfd = READ_ONCE(sqe->fd);
req->open.mask = READ_ONCE(sqe->len);
--
2.24.0