From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E94AA234989 for ; Tue, 18 Feb 2025 11:29:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739878153; cv=none; b=NQBjC21Q76o0xjZK2U260Khr8ok5h6M05lqz8bRyHGCuyWGDFHfJah335IB1TUWUoyOk/zBa4OBY6oL3LMAt0t65BmulwjffOKaan2yIoCONI4O6e3xQHo0iEGxJKqWFRzdhl6mWPhS93itnn3Bdxywi5WqBUWLFEe1JSv6+D2s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739878153; c=relaxed/simple; bh=U2c64qBw8zgEq7kHitCThqhOUpDvhrEAG1oGmLYjZzE=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=J1BNm/NpuwcCqFIpvz5tc5X7DFLt21WdWorg8Mgt6RZq10zWmrAItywJItvXk0fsU1eEmSNcTGEUORiMYgzBNURV+ZGMVvcDVdeGYLPs+EHspnt2eS/nyLmjAX4O0T1qaJohHDie0/M/G3xy2Yp0Xn38Tv+fZjzh+uhgdyvhCfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iNX7AePJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iNX7AePJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09D39C4CEE7; Tue, 18 Feb 2025 11:29:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739878152; bh=U2c64qBw8zgEq7kHitCThqhOUpDvhrEAG1oGmLYjZzE=; h=Subject:To:Cc:From:Date:From; b=iNX7AePJ/XZJ6jJ3cTd6H/IF45nIxKpFiwfkLMiUKnXyZPdvsH9AJ8IjWVworGRPv 0wXc+THDcDzB0KqpbfK7xh4yDQQ3Z7HMZcJGpLiql/8dnmf0lgAvnXftUukQN5zFBN kgVpvS7sizKLTATIHS6J70uzB2SotgmyfEothbcE= Subject: FAILED: patch "[PATCH] io_uring/kbuf: reallocate buf lists on upgrade" failed to apply to 6.1-stable tree To: asml.silence@gmail.com,axboe@kernel.dk,pumpkin@devco.re Cc: From: Date: Tue, 18 Feb 2025 12:29:01 +0100 Message-ID: <2025021801-splinter-sappy-56b3@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-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 . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 8802766324e1f5d414a81ac43365c20142e85603 # git commit -s git send-email --to '' --in-reply-to '2025021801-splinter-sappy-56b3@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8802766324e1f5d414a81ac43365c20142e85603 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Wed, 12 Feb 2025 13:46:46 +0000 Subject: [PATCH] io_uring/kbuf: reallocate buf lists on upgrade IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it was created for legacy selected buffer and has been emptied. It violates the requirement that most of the field should stay stable after publish. Always reallocate it instead. Cc: stable@vger.kernel.org Reported-by: Pumpkin Chang Fixes: 2fcabce2d7d34 ("io_uring: disallow mixed provided buffer group registrations") Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 04bf493eecae..8e72de7712ac 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -415,6 +415,13 @@ void io_destroy_buffers(struct io_ring_ctx *ctx) } } +static void io_destroy_bl(struct io_ring_ctx *ctx, struct io_buffer_list *bl) +{ + scoped_guard(mutex, &ctx->mmap_lock) + WARN_ON_ONCE(xa_erase(&ctx->io_bl_xa, bl->bgid) != bl); + io_put_bl(ctx, bl); +} + int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf); @@ -636,12 +643,13 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg) /* if mapped buffer ring OR classic exists, don't allow */ if (bl->flags & IOBL_BUF_RING || !list_empty(&bl->buf_list)) return -EEXIST; - } else { - free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL); - if (!bl) - return -ENOMEM; + io_destroy_bl(ctx, bl); } + free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL); + if (!bl) + return -ENOMEM; + mmap_offset = (unsigned long)reg.bgid << IORING_OFF_PBUF_SHIFT; ring_size = flex_array_size(br, bufs, reg.ring_entries);