From 8b3d1de0e82c391eb19f2acac80df54ed632a2fd Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sat, 8 Feb 2020 13:28:02 +0300 Subject: [PATCH] io_uring: fix double prep iovec leak to #26323588 commit 5f798beaf35d79355cbf18019c1993a84475a2c3 upstream. Requests may be prepared multiple times with ->io allocated (i.e. async prepared). Preparation functions don't handle it and forget about previously allocated resources. This may happen in case of: - spurious defer_check - non-head (i.e. async prepared) request executed in sync (via nxt). Make the handlers check, whether they already allocated resources, which is true IFF REQ_F_NEED_CLEANUP is set. Cc: stable@vger.kernel.org # 5.5 Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe Signed-off-by: Joseph Qi Acked-by: Xiaoguang Wang --- fs/io_uring.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index c8f30dfadeff..e3c8cb971eae 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2202,7 +2202,8 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, if (unlikely(!(req->file->f_mode & FMODE_READ))) return -EBADF; - if (!req->io) + /* either don't need iovec imported or already have it */ + if (!req->io || req->flags & REQ_F_NEED_CLEANUP) return 0; io = req->io; @@ -2290,7 +2291,8 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, if (unlikely(!(req->file->f_mode & FMODE_WRITE))) return -EBADF; - if (!req->io) + /* either don't need iovec imported or already have it */ + if (!req->io || req->flags & REQ_F_NEED_CLEANUP) return 0; io = req->io; @@ -2990,6 +2992,9 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (!io || req->opcode == IORING_OP_SEND) return 0; + /* iovec is already imported */ + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; io->msg.iov = io->msg.fast_iov; ret = sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags, @@ -3140,6 +3145,9 @@ static int io_recvmsg_prep(struct io_kiocb *req, if (!io || req->opcode == IORING_OP_RECV) return 0; + /* iovec is already imported */ + if (req->flags & REQ_F_NEED_CLEANUP) + return 0; io->msg.iov = io->msg.fast_iov; ret = recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags, -- GitLab