The patch below does not apply to the 5.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 99bc4c38537d774e667d043c520914082da19abf Mon Sep 17 00:00:00 2001
From: Pavel Begunkov asml.silence@gmail.com Date: Fri, 7 Feb 2020 22:04:45 +0300 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()
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
diff --git a/fs/io_uring.c b/fs/io_uring.c index ebf3b43fb91b..5353e96029c7 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), };
/* @@ -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 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, } out_free: kfree(iovec); + req->flags &= ~REQ_F_NEED_CLEANUP; return ret; }
@@ -2342,6 +2352,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt, } } out_free: + req->flags &= ~REQ_F_NEED_CLEANUP; kfree(iovec); return ret; } @@ -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) {