From 343ae23049ddc7712d4bdd72d6a5afb8c653c1e2 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 6 Feb 2020 19:51:16 +0300 Subject: [PATCH] io_uring: fix deferred req iovec leak to #26323588 commit 1e95081cb5b4cf77065d37866f57cf3c90a3df78 upstream. After defer, a request will be prepared, that includes allocating iovec if needed, and then submitted through io_wq_submit_work() but not custom handler (e.g. io_rw_async()/io_sendrecv_async()). However, it'll leak iovec, as it's in io-wq and the code goes as follows: io_read() { if (!io_wq_current_is_worker()) kfree(iovec); } Put all deallocation logic in io_{read,write,send,recv}(), which will leave the memory, if going async with -EAGAIN. It also fixes a leak after failed io_alloc_async_ctx() in io_{recv,send}_msg(). 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 | 47 ++++++++++++----------------------------------- 1 file changed, 12 insertions(+), 35 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 6f3da2e1591d..51006b182248 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2141,17 +2141,6 @@ static int io_alloc_async_ctx(struct io_kiocb *req) return req->io == NULL; } -static void io_rw_async(struct io_wq_work **workptr) -{ - struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); - struct iovec *iov = NULL; - - if (req->io->rw.iov != req->io->rw.fast_iov) - iov = req->io->rw.iov; - io_wq_submit_work(workptr); - kfree(iov); -} - static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size, struct iovec *iovec, struct iovec *fast_iov, struct iov_iter *iter) @@ -2164,7 +2153,6 @@ static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size, io_req_map_rw(req, io_size, iovec, fast_iov, iter); } - req->work.func = io_rw_async; return 0; } @@ -2251,8 +2239,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, } } out_free: - if (!io_wq_current_is_worker()) - kfree(iovec); + kfree(iovec); return ret; } @@ -2357,8 +2344,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt, } } out_free: - if (!io_wq_current_is_worker()) - kfree(iovec); + kfree(iovec); return ret; } @@ -2953,19 +2939,6 @@ static int io_sync_file_range(struct io_kiocb *req, struct io_kiocb **nxt, return 0; } -#if defined(CONFIG_NET) -static void io_sendrecv_async(struct io_wq_work **workptr) -{ - struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); - struct iovec *iov = NULL; - - if (req->io->rw.iov != req->io->rw.fast_iov) - iov = req->io->msg.iov; - io_wq_submit_work(workptr); - kfree(iov); -} -#endif - static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { #if defined(CONFIG_NET) @@ -3034,17 +3007,19 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt, if (force_nonblock && ret == -EAGAIN) { if (req->io) return -EAGAIN; - if (io_alloc_async_ctx(req)) + if (io_alloc_async_ctx(req)) { + if (kmsg && kmsg->iov != kmsg->fast_iov) + kfree(kmsg->iov); return -ENOMEM; + } memcpy(&req->io->msg, &io.msg, sizeof(io.msg)); - req->work.func = io_sendrecv_async; return -EAGAIN; } if (ret == -ERESTARTSYS) ret = -EINTR; } - if (!io_wq_current_is_worker() && kmsg && kmsg->iov != kmsg->fast_iov) + if (kmsg && kmsg->iov != kmsg->fast_iov) kfree(kmsg->iov); io_cqring_add_event(req, ret); if (ret < 0) @@ -3178,17 +3153,19 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt, if (force_nonblock && ret == -EAGAIN) { if (req->io) return -EAGAIN; - if (io_alloc_async_ctx(req)) + if (io_alloc_async_ctx(req)) { + if (kmsg && kmsg->iov != kmsg->fast_iov) + kfree(kmsg->iov); return -ENOMEM; + } memcpy(&req->io->msg, &io.msg, sizeof(io.msg)); - req->work.func = io_sendrecv_async; return -EAGAIN; } if (ret == -ERESTARTSYS) ret = -EINTR; } - if (!io_wq_current_is_worker() && kmsg && kmsg->iov != kmsg->fast_iov) + if (kmsg && kmsg->iov != kmsg->fast_iov) kfree(kmsg->iov); io_cqring_add_event(req, ret); if (ret < 0) -- GitLab