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Message-Id: <03aa734fcea29805635689cc2f1aa648f23b5cd3.1581102250.git.asml.silence@gmail.com>
Date: Fri, 7 Feb 2020 22:04:45 +0300
From: Pavel Begunkov <asml.silence@...il.com>
To: Jens Axboe <axboe@...nel.dk>, io-uring@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH] io_uring: fix iovec leaks
Allocated iovec is freed only in io_{read,write,send,recv)(), and just
leaves it if an error occured. There are plenty of such cases:
- cancellation of non-head requests
- fail grabbing files in __io_queue_sqe()
- set REQ_F_NOWAIT and returning in __io_queue_sqe()
- etc.
Add REQ_F_NEED_CLEANUP, which will force such requests with custom
allocated resourses go through cleanup handlers on put.
Signed-off-by: Pavel Begunkov <asml.silence@...il.com>
---
fs/io_uring.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 49 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 1914351ebd5e..d699695ef809 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -478,6 +478,7 @@ enum {
REQ_F_MUST_PUNT_BIT,
REQ_F_TIMEOUT_NOSEQ_BIT,
REQ_F_COMP_LOCKED_BIT,
+ REQ_F_NEED_CLEANUP_BIT,
};
enum {
@@ -516,6 +517,8 @@ enum {
REQ_F_TIMEOUT_NOSEQ = BIT(REQ_F_TIMEOUT_NOSEQ_BIT),
/* completion under lock */
REQ_F_COMP_LOCKED = BIT(REQ_F_COMP_LOCKED_BIT),
+ /* needs cleanup */
+ REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
};
@@ -749,6 +752,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
unsigned nr_args);
static int io_grab_files(struct io_kiocb *req);
static void io_ring_file_ref_flush(struct fixed_file_data *data);
+static void io_cleanup_req(struct io_kiocb *req);
static struct kmem_cache *req_cachep;
@@ -1236,6 +1240,9 @@ static void __io_free_req(struct io_kiocb *req)
{
__io_req_aux_free(req);
+ if (req->flags & REQ_F_NEED_CLEANUP)
+ io_cleanup_req(req);
+
if (req->flags & REQ_F_INFLIGHT) {
struct io_ring_ctx *ctx = req->ctx;
unsigned long flags;
@@ -2129,6 +2136,8 @@ static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size,
req->io->rw.iov = req->io->rw.fast_iov;
memcpy(req->io->rw.iov, fast_iov,
sizeof(struct iovec) * iter->nr_segs);
+ } else {
+ req->flags |= REQ_F_NEED_CLEANUP;
}
}
@@ -2239,6 +2248,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt,
}
out_free:
kfree(iovec);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
return ret;
}
@@ -2343,6 +2353,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
}
}
out_free:
+ req->flags &= ~REQ_F_NEED_CLEANUP;
kfree(iovec);
return ret;
}
@@ -2943,6 +2954,7 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
#if defined(CONFIG_NET)
struct io_sr_msg *sr = &req->sr_msg;
struct io_async_ctx *io = req->io;
+ int ret;
sr->msg_flags = READ_ONCE(sqe->msg_flags);
sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -2952,8 +2964,11 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return 0;
io->msg.iov = io->msg.fast_iov;
- return sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
+ ret = sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
&io->msg.iov);
+ if (!ret)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return ret;
#else
return -EOPNOTSUPP;
#endif
@@ -3011,6 +3026,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
kfree(kmsg->iov);
return -ENOMEM;
}
+ req->flags |= REQ_F_NEED_CLEANUP;
memcpy(&req->io->msg, &io.msg, sizeof(io.msg));
return -EAGAIN;
}
@@ -3020,6 +3036,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
if (kmsg && kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
io_cqring_add_event(req, ret);
if (ret < 0)
req_set_fail_links(req);
@@ -3087,6 +3104,7 @@ static int io_recvmsg_prep(struct io_kiocb *req,
#if defined(CONFIG_NET)
struct io_sr_msg *sr = &req->sr_msg;
struct io_async_ctx *io = req->io;
+ int ret;
sr->msg_flags = READ_ONCE(sqe->msg_flags);
sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
@@ -3096,8 +3114,11 @@ static int io_recvmsg_prep(struct io_kiocb *req,
return 0;
io->msg.iov = io->msg.fast_iov;
- return recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
+ ret = recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
&io->msg.uaddr, &io->msg.iov);
+ if (!ret)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return ret;
#else
return -EOPNOTSUPP;
#endif
@@ -3158,6 +3179,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
return -ENOMEM;
}
memcpy(&req->io->msg, &io.msg, sizeof(io.msg));
+ req->flags |= REQ_F_NEED_CLEANUP;
return -EAGAIN;
}
if (ret == -ERESTARTSYS)
@@ -3166,6 +3188,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
if (kmsg && kmsg->iov != kmsg->fast_iov)
kfree(kmsg->iov);
+ req->flags &= ~REQ_F_NEED_CLEANUP;
io_cqring_add_event(req, ret);
if (ret < 0)
req_set_fail_links(req);
@@ -4176,6 +4199,30 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return -EIOCBQUEUED;
}
+static void io_cleanup_req(struct io_kiocb *req)
+{
+ struct io_async_ctx *io = req->io;
+
+ switch (req->opcode) {
+ case IORING_OP_READV:
+ case IORING_OP_READ_FIXED:
+ case IORING_OP_READ:
+ case IORING_OP_WRITEV:
+ case IORING_OP_WRITE_FIXED:
+ case IORING_OP_WRITE:
+ if (io->rw.iov != io->rw.fast_iov)
+ kfree(io->rw.iov);
+ break;
+ case IORING_OP_SENDMSG:
+ case IORING_OP_RECVMSG:
+ if (io->msg.iov != io->msg.fast_iov)
+ kfree(io->msg.iov);
+ break;
+ }
+
+ req->flags &= ~REQ_F_NEED_CLEANUP;
+}
+
static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
struct io_kiocb **nxt, bool force_nonblock)
{
--
2.24.0
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