From patchwork Wed Aug 28 15:46:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 13781542 Received: from mail-io1-f41.google.com (mail-io1-f41.google.com [209.85.166.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BBD083A18 for ; Wed, 28 Aug 2024 15:46:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.41 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724859980; cv=none; b=szVDx7wh9drkEbWCg9H+o0Yk3NhgmenC2b53Svu/KTZM4uq3t87qJ88YYiDDJxn0YaFURN+a31/rKJg+gZzyoejmefT/3N+Gg+Ws3N9J9mStNJBRadQrkGhQnSJV2LAhyE6kuGTliLmLiVn/3WIJwmgJIMRTlLTDgznxmgidloc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724859980; c=relaxed/simple; bh=c3kWt2JnvYEZcsYhdePGzMlcu4+ycTX0/V4D4Vq3I6M=; h=Message-ID:Date:MIME-Version:To:From:Subject:Cc:Content-Type; b=guhEfHv2mtE1tr3qSUSaWyHjA0CrfuDzTiZaTJA/s3c5ZygVmFpoCftD+7Ru//b8/vQ5OrfIylF2IlVnM+zTiDdNelAfHTgqBJnScjUaNP3OTBCvAXR6/AFQQsjXmcrWaSMLnBTWU5hDDhO6FE0RhKRQG0hJooS5rVJJzJrNjqg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=ZpioeGGA; arc=none smtp.client-ip=209.85.166.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="ZpioeGGA" Received: by mail-io1-f41.google.com with SMTP id ca18e2360f4ac-82784c8bca5so218701039f.0 for ; Wed, 28 Aug 2024 08:46:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1724859976; x=1725464776; darn=vger.kernel.org; h=content-transfer-encoding:cc:subject:from:to:content-language :user-agent:mime-version:date:message-id:from:to:cc:subject:date :message-id:reply-to; bh=cFPQ3A3CA9dg2JwBA2KnSdZRy7rJHdQN+nmim/WYFBI=; b=ZpioeGGA5QdDbYZC2/q7sk2NcGBVxdCcRcuzHllqhPzYmHs+a56u4bkWFFKKytvJ98 GKjAdlsTA/Qm91Bu4u416UQYfdHE76bJ8ckee/yUCjRnQMDSSBLJWU1jufYjDMGTGvra yT1L5/j+C4HWDLIEhTWUUqQUTzi9LFd19iY6V9JPpj3iazPxlDzdWg6+lr0EoKigR3sG QAJbXLk2nof0KfnBcZHCI5RwHJlhFLO0UlcqhJRvFeOsLeFdx7z4CWssHUjYO1Y/4LrK VqadHHSq4QZmPFeUu0ylpm06gOQ9ci1Uv7l+I6b0vSKSVDBor8r5wjo9Y98QKgOZdXCu xeYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724859976; x=1725464776; h=content-transfer-encoding:cc:subject:from:to:content-language :user-agent:mime-version:date:message-id:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=cFPQ3A3CA9dg2JwBA2KnSdZRy7rJHdQN+nmim/WYFBI=; b=XIaZAgKK93UEkKgMrz09EU+1VNsyPW0lFZXJmPJpM3JiIpiaytLvqCG8MFJ0wsyE2B K0iuMnzjT6/75MadtTsNzEbNtshvPZqBMFpsMDq76FL7RRr8+tfo8LjhI0Qa6NUtmM2l igkDcZ7fj8M74kUwRzK8h0Hk3UHOJI5HfAeLehTnr1GC4xJjtRVwUJYlohOCIgkwp7Ft 4E7La16qpUhzNXI2zuiJ34rcmTK98GYgKqNZm7oWHOmSmLURMsO8r1++P3bYiF9XrPUX A24CW2T8LJ/9rF1ESLDjkLzVo+T8GpE2lLaWrkwk1gcfN5eRWcakySyJxxtsENNgbFy0 fMXQ== X-Gm-Message-State: AOJu0YxqP4+Q+nkLP2627wsve2jJI6hwCNuTpuP2cfRzNoQghoeSMGxj c5sOqIOJfN+sf2GgSfscPxe7/+pc8jUp5O/vIZKBPHhrOsQbMEipmR0O6OvDO2BhclRcXDfhNWA p X-Google-Smtp-Source: AGHT+IEJIGh9AIO8xs64VCgCcpkTuxEyHWct1ROybQtG1wFPFSt58bPIGsWOWlf2B6j9wwqLTx7WSg== X-Received: by 2002:a05:6602:3fcb:b0:805:afed:cea1 with SMTP id ca18e2360f4ac-82787376a19mr1905416539f.14.1724859975862; Wed, 28 Aug 2024 08:46:15 -0700 (PDT) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-82a0ffdda7fsm2849939f.12.2024.08.28.08.46.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 28 Aug 2024 08:46:15 -0700 (PDT) Message-ID: Date: Wed, 28 Aug 2024 09:46:14 -0600 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: io-uring From: Jens Axboe Subject: [PATCH] io_uring/rsrc: ensure compat iovecs are copied correctly Cc: Gabriel Krisman Bertazi For buffer registration (or updates), a userspace iovec is copied in and updated. If the application is within a compat syscall, then the iovec type is compat_iovec rather than iovec. However, the type used in __io_sqe_buffers_update() and io_sqe_buffers_register() is always struct iovec, and hence the source is incremented by the size of a non-compat iovec in the loop. This misses every other iovec in the source, and will run into garbage half way through the copies and return -EFAULT to the application. Maintain the source address separately and assign to our user vec pointer, so that copies always happen from the right source address. Fixes: f4eaf8eda89e ("io_uring/rsrc: Drop io_copy_iov in favor of iovec API") Signed-off-by: Jens Axboe Reviewed-by: Gabriel Krisman Bertazi diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index a860516bf448..b38d0ef41ef1 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -394,10 +394,11 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, struct io_uring_rsrc_update2 *up, unsigned int nr_args) { - struct iovec __user *uvec = u64_to_user_ptr(up->data); u64 __user *tags = u64_to_user_ptr(up->tags); struct iovec fast_iov, *iov; struct page *last_hpage = NULL; + struct iovec __user *uvec; + u64 user_data = up->data; __u32 done; int i, err; @@ -410,7 +411,8 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, struct io_mapped_ubuf *imu; u64 tag = 0; - iov = iovec_from_user(&uvec[done], 1, 1, &fast_iov, ctx->compat); + uvec = u64_to_user_ptr(user_data); + iov = iovec_from_user(uvec, 1, 1, &fast_iov, ctx->compat); if (IS_ERR(iov)) { err = PTR_ERR(iov); break; @@ -443,6 +445,10 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, ctx->user_bufs[i] = imu; *io_get_tag_slot(ctx->buf_data, i) = tag; + if (ctx->compat) + user_data += sizeof(struct compat_iovec); + else + user_data += sizeof(struct iovec); } return done ? done : err; } @@ -949,7 +955,7 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, struct page *last_hpage = NULL; struct io_rsrc_data *data; struct iovec fast_iov, *iov = &fast_iov; - const struct iovec __user *uvec = (struct iovec * __user) arg; + const struct iovec __user *uvec; int i, ret; BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16)); @@ -972,7 +978,8 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { if (arg) { - iov = iovec_from_user(&uvec[i], 1, 1, &fast_iov, ctx->compat); + uvec = (struct iovec * __user) arg; + iov = iovec_from_user(uvec, 1, 1, &fast_iov, ctx->compat); if (IS_ERR(iov)) { ret = PTR_ERR(iov); break; @@ -980,6 +987,10 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, ret = io_buffer_validate(iov); if (ret) break; + if (ctx->compat) + arg += sizeof(struct compat_iovec); + else + arg += sizeof(struct iovec); } if (!iov->iov_base && *io_get_tag_slot(data, i)) {