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io_uring: fix iovec leaks

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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()

Add REQ_F_NEED_CLEANUP, which will force such requests with custom
allocated resourses go through cleanup handlers on put.

Cc: stable@vger.kernel.org # 5.5
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-02-07 22:04:45 +03:00 committed by Jens Axboe
parent e96e977992
commit 99bc4c3853
1 changed files with 49 additions and 2 deletions
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51
fs/io_uring.c
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@ -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),
};
/*
@ -748,6 +751,7 @@ 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;
@ -1235,6 +1239,9 @@ 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;
@ -2128,6 +2135,8 @@ 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;
}
}
@ -2238,6 +2247,7 @@ copy_iov:
}
out_free:
kfree(iovec);
req->flags &= ~REQ_F_NEED_CLEANUP;
return ret;
}
@ -2342,6 +2352,7 @@ copy_iov:
}
}
out_free:
req->flags &= ~REQ_F_NEED_CLEANUP;
kfree(iovec);
return ret;
}
@ -2948,6 +2959,7 @@ 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));
@ -2957,8 +2969,11 @@ 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
@ -3016,6 +3031,7 @@ 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;
}
@ -3025,6 +3041,7 @@ 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);
@ -3092,6 +3109,7 @@ 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));
@ -3101,8 +3119,11 @@ 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
@ -3163,6 +3184,7 @@ 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)
@ -3171,6 +3193,7 @@ 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);
@ -4181,6 +4204,30 @@ 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)
{