From patchwork Fri May 27 16:53:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaoguang Wang X-Patchwork-Id: 12863578 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB436C4332F for ; Fri, 27 May 2022 16:53:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232531AbiE0Qxn (ORCPT ); Fri, 27 May 2022 12:53:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233988AbiE0Qxl (ORCPT ); Fri, 27 May 2022 12:53:41 -0400 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6EAF8ED70C for ; Fri, 27 May 2022 09:53:37 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---0VEY.2mw_1653670414; Received: from localhost(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0VEY.2mw_1653670414) by smtp.aliyun-inc.com(127.0.0.1); Sat, 28 May 2022 00:53:34 +0800 From: Xiaoguang Wang To: io-uring@vger.kernel.org Cc: axboe@kernel.dk, asml.silence@gmail.com Subject: [PATCH 1/2] io_uring: fix file leaks around io_fixed_fd_install() Date: Sat, 28 May 2022 00:53:32 +0800 Message-Id: <20220527165333.55212-2-xiaoguang.wang@linux.alibaba.com> X-Mailer: git-send-email 2.14.4.44.g2045bb6 In-Reply-To: <20220527165333.55212-1-xiaoguang.wang@linux.alibaba.com> References: <20220527165333.55212-1-xiaoguang.wang@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org io_fixed_fd_install() may fail for many reasons, such as short of free fixed file bitmap, memory allocation failures, etc. When these errors happen, current code forgets to fput(file) correspondingly. This patch will fix resource leaks around io_fixed_fd_install(), meanwhile io_fixed_fd_install() and io_install_fixed_file() are basically similar, fold them into one function. Signed-off-by: Xiaoguang Wang --- fs/io_uring.c | 77 ++++++++++++++++++++++++++--------------------------------- 1 file changed, 34 insertions(+), 43 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index d50bbf8de4fb..ff50e5f1753d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1364,8 +1364,8 @@ static void io_req_task_queue(struct io_kiocb *req); static void __io_submit_flush_completions(struct io_ring_ctx *ctx); static int io_req_prep_async(struct io_kiocb *req); -static int io_install_fixed_file(struct io_kiocb *req, struct file *file, - unsigned int issue_flags, u32 slot_index); +static int io_install_fixed_file(struct io_kiocb *req, unsigned int issue_flags, + struct file *file, u32 slot); static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags); static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer); @@ -5438,36 +5438,6 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx) return -ENFILE; } -static int io_fixed_fd_install(struct io_kiocb *req, unsigned int issue_flags, - struct file *file, unsigned int file_slot) -{ - bool alloc_slot = file_slot == IORING_FILE_INDEX_ALLOC; - struct io_ring_ctx *ctx = req->ctx; - int ret; - - if (alloc_slot) { - io_ring_submit_lock(ctx, issue_flags); - ret = io_file_bitmap_get(ctx); - if (unlikely(ret < 0)) { - io_ring_submit_unlock(ctx, issue_flags); - return ret; - } - - file_slot = ret; - } else { - file_slot--; - } - - ret = io_install_fixed_file(req, file, issue_flags, file_slot); - if (alloc_slot) { - io_ring_submit_unlock(ctx, issue_flags); - if (!ret) - return file_slot; - } - - return ret; -} - static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) { struct open_flags op; @@ -5520,11 +5490,14 @@ static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) file->f_flags &= ~O_NONBLOCK; fsnotify_open(file); - if (!fixed) + if (!fixed) { fd_install(ret, file); - else - ret = io_fixed_fd_install(req, issue_flags, file, - req->open.file_slot); + } else { + ret = io_install_fixed_file(req, issue_flags, file, + req->open.file_slot); + if (ret < 0) + fput(file); + } err: putname(req->open.filename); req->flags &= ~REQ_F_NEED_CLEANUP; @@ -6603,8 +6576,10 @@ static int io_accept(struct io_kiocb *req, unsigned int issue_flags) fd_install(fd, file); ret = fd; } else { - ret = io_fixed_fd_install(req, issue_flags, file, - accept->file_slot); + ret = io_install_fixed_file(req, issue_flags, file, + accept->file_slot); + if (ret < 0) + fput(file); } if (!(req->flags & REQ_F_APOLL_MULTISHOT)) { @@ -6676,8 +6651,10 @@ static int io_socket(struct io_kiocb *req, unsigned int issue_flags) fd_install(fd, file); ret = fd; } else { - ret = io_fixed_fd_install(req, issue_flags, file, + ret = io_install_fixed_file(req, issue_flags, file, sock->file_slot); + if (ret < 0) + fput(file); } __io_req_complete(req, issue_flags, ret, 0); return 0; @@ -10130,15 +10107,27 @@ static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, return 0; } -static int io_install_fixed_file(struct io_kiocb *req, struct file *file, - unsigned int issue_flags, u32 slot_index) +static int io_install_fixed_file(struct io_kiocb *req, unsigned int issue_flags, + struct file *file, u32 slot) { struct io_ring_ctx *ctx = req->ctx; bool needs_switch = false; struct io_fixed_file *file_slot; int ret = -EBADF; + bool alloc_slot = slot == IORING_FILE_INDEX_ALLOC; + int slot_index; io_ring_submit_lock(ctx, issue_flags); + if (alloc_slot) { + slot_index = io_file_bitmap_get(ctx); + if (unlikely(slot_index < 0)) { + io_ring_submit_unlock(ctx, issue_flags); + return slot_index; + } + } else { + slot_index = slot - 1; + } + if (file->f_op == &io_uring_fops) goto err; ret = -ENXIO; @@ -10178,8 +10167,10 @@ static int io_install_fixed_file(struct io_kiocb *req, struct file *file, if (needs_switch) io_rsrc_node_switch(ctx, ctx->file_data); io_ring_submit_unlock(ctx, issue_flags); - if (ret) - fput(file); + if (alloc_slot) { + if (!ret) + return slot_index; + } return ret; } From patchwork Fri May 27 16:53:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaoguang Wang X-Patchwork-Id: 12863577 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8422C433F5 for ; Fri, 27 May 2022 16:53:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233988AbiE0Qxn (ORCPT ); Fri, 27 May 2022 12:53:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236944AbiE0Qxn (ORCPT ); Fri, 27 May 2022 12:53:43 -0400 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C4AAED70E for ; Fri, 27 May 2022 09:53:39 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=xiaoguang.wang@linux.alibaba.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---0VEXwEoG_1653670415; Received: from localhost(mailfrom:xiaoguang.wang@linux.alibaba.com fp:SMTPD_---0VEXwEoG_1653670415) by smtp.aliyun-inc.com(127.0.0.1); Sat, 28 May 2022 00:53:35 +0800 From: Xiaoguang Wang To: io-uring@vger.kernel.org Cc: axboe@kernel.dk, asml.silence@gmail.com Subject: [PATCH 2/2] io_uring: defer alloc_hint update to io_file_bitmap_set() Date: Sat, 28 May 2022 00:53:33 +0800 Message-Id: <20220527165333.55212-3-xiaoguang.wang@linux.alibaba.com> X-Mailer: git-send-email 2.14.4.44.g2045bb6 In-Reply-To: <20220527165333.55212-1-xiaoguang.wang@linux.alibaba.com> References: <20220527165333.55212-1-xiaoguang.wang@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org io_file_bitmap_get() returns a free bitmap slot, but if it isn't used later, such as io_queue_rsrc_removal() returns error, in this case, we should not update alloc_hint at all, which still should be considered as a valid candidate for next io_file_bitmap_get() calls. To fix this issue, only update alloc_hint in io_file_bitmap_set(). Signed-off-by: Xiaoguang Wang --- fs/io_uring.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ff50e5f1753d..811007e055c6 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5419,15 +5419,11 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx) unsigned long nr = ctx->nr_user_files; int ret; - if (table->alloc_hint >= nr) - table->alloc_hint = 0; - do { ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint); - if (ret != nr) { - table->alloc_hint = ret + 1; + if (ret != nr) return ret; - } + if (!table->alloc_hint) break; @@ -9650,12 +9646,15 @@ static void io_free_file_tables(struct io_file_table *table) table->bitmap = NULL; } -static inline void io_file_bitmap_set(struct io_file_table *table, int bit) +static inline void io_file_bitmap_set(struct io_ring_ctx *ctx, int bit) { + struct io_file_table *table = &ctx->file_table; + WARN_ON_ONCE(test_bit(bit, table->bitmap)); __set_bit(bit, table->bitmap); - if (bit == table->alloc_hint) - table->alloc_hint++; + table->alloc_hint = bit + 1; + if (table->alloc_hint >= ctx->nr_user_files) + table->alloc_hint = 0; } static inline void io_file_bitmap_clear(struct io_file_table *table, int bit) @@ -10080,7 +10079,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, } file_slot = io_fixed_file_slot(&ctx->file_table, i); io_fixed_file_set(file_slot, file); - io_file_bitmap_set(&ctx->file_table, i); + io_file_bitmap_set(ctx, i); } io_rsrc_node_switch(ctx, NULL); @@ -10161,7 +10160,7 @@ static int io_install_fixed_file(struct io_kiocb *req, unsigned int issue_flags, if (!ret) { *io_get_tag_slot(ctx->file_data, slot_index) = 0; io_fixed_file_set(file_slot, file); - io_file_bitmap_set(&ctx->file_table, slot_index); + io_file_bitmap_set(ctx, slot_index); } err: if (needs_switch) @@ -10284,7 +10283,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx, } *io_get_tag_slot(data, i) = tag; io_fixed_file_set(file_slot, file); - io_file_bitmap_set(&ctx->file_table, i); + io_file_bitmap_set(ctx, i); } }