From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 63EE54A2E1D for ; Thu, 2 Jul 2026 13:53:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783000408; cv=none; b=mGH7Stx2u3X0TO4k2lhPObcC+tg87T55dqC07eNO7sLTZY0Tk3OC709lgbfP+NuA5Hw8zuQMiCZzstMkg8INfPh5HzKvu6+5vBIfsYJe1Fso8Zk4EDL9EjFhkgF3qOMYPyb+GHMjyFQutpRLejljGhQsyki6+mvfVnWjKMV2TXo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783000408; c=relaxed/simple; bh=+MwmoH2BUtLm3SxhQxTe9ykcKSIo+WmnrGygX26xr5g=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=gqt/2+xEsugXhZJQDOGKYM8L2Iq+lI7IGk+MQ1TEEBLFMeyBT8ZjWsPJND8t8BUhlyjghXVA6gXIEbGq/fIV4VjtUNafeouC1JPcMI4JwrFlW14wTkXBh9j6lGgZFbMMJRRdKoM6giNkJ46DAjLUwXUBEBifchiamrAHsPE9QVQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yztq0VXQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yztq0VXQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B9EF1F000E9; Thu, 2 Jul 2026 13:53:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783000401; bh=vt6W9zHCDlTHbTXzTrPoHPOsnyM2w5dSfiGowvkRmvw=; h=Subject:To:Cc:From:Date; b=yztq0VXQ9Fs+7JyCBtvE1SBQ7Z7Pv2cNQ2SR8t1mokgvOVMD1erE0bzoxGDi053Ov iKy33C3uPUrmaT3lztZN0CwelAY2/lmH6QvxB2JiVwxyFARYpKhV7HdhoSPIuLqpNL 1UpQwj6kPVFbS+bWDadcgv/1tvodbqW4AFsqTsFI= Subject: FAILED: patch "[PATCH] i2c: core: fix adapter registration race" failed to apply to 6.6-stable tree To: johan@kernel.org,wsa+renesas@sang-engineering.com Cc: From: Date: Thu, 02 Jul 2026 15:53:32 +0200 Message-ID: <2026070232-straddle-keenness-fbbc@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 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x ba14d7cf2fe7284610a29854bdff22b2537d3ce6 # git commit -s git send-email --to '' --in-reply-to '2026070232-straddle-keenness-fbbc@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ba14d7cf2fe7284610a29854bdff22b2537d3ce6 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 11 May 2026 16:37:12 +0200 Subject: [PATCH] i2c: core: fix adapter registration race Adapters can be looked up based on their id using i2c_get_adapter() which takes a reference to the embedded struct device. Make sure that the adapter (including its struct device) has been initialised before adding it to the IDR to avoid accessing uninitialised data which could, for example, lead to NULL-pointer dereferences or use-after-free. Note that the i2c-dev chardev, which is registered from a bus notifier, currently uses i2c_get_adapter() so the adapter needs to be added to the IDR before registration. Fixes: 6e13e6418418 ("i2c: Add i2c_add_numbered_adapter()") Cc: stable@vger.kernel.org # 2.6.22 Signed-off-by: Johan Hovold Signed-off-by: Wolfram Sang diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index fdf7d7d50f79..01a984d3ca0e 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1580,6 +1580,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap) adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root); + mutex_lock(&core_lock); + idr_replace(&i2c_adapter_idr, adap, adap->nr); + mutex_unlock(&core_lock); + res = device_add(&adap->dev); if (res) { pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); @@ -1638,7 +1642,7 @@ static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) int id; mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); + id = idr_alloc(&i2c_adapter_idr, NULL, adap->nr, adap->nr + 1, GFP_KERNEL); mutex_unlock(&core_lock); if (WARN(id < 0, "couldn't get idr")) return id == -ENOSPC ? -EBUSY : id; @@ -1672,7 +1676,7 @@ int i2c_add_adapter(struct i2c_adapter *adapter) } mutex_lock(&core_lock); - id = idr_alloc(&i2c_adapter_idr, adapter, + id = idr_alloc(&i2c_adapter_idr, NULL, __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); mutex_unlock(&core_lock); if (WARN(id < 0, "couldn't get idr"))