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 44808423A7C; Tue, 31 Mar 2026 16:52:28 +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=1774975948; cv=none; b=gEorX1tRSDP4ZfU3Wjwi/uosksp46cuXFBIlu5BrhiGshmx9Hagr9AH101nL7FglOKZJHtASyusLID1vs+PbNX8TPhpYg5G1EmTelohOdXBSqOu0/sNo/fAaXo/mhvMWTKWdJ3jwHJ/oyKvBsXF9jVOvkBkg3C6ietHhnOpJk54= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774975948; c=relaxed/simple; bh=az/tbwwybVECnE/sghykLnICiGoGfPtrsSkbz7HVHT4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h2up5VTxIUsfHPNUvxGtF9DhfDE3pEfw+e52V8MzOP6+JaveEtOBbx/ck5wsxSZ3gSKHuFkAf1XSb1b4eJnQD4aXwn02sUHS0rJ2jajiTZxOlRvzA48QGT43jzNcYAnNHQE8TWOI6w0obkWKVB3XVHJEUKkJ517w5zahp3h/D3g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ip8Nrdl8; 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="Ip8Nrdl8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE9FEC19423; Tue, 31 Mar 2026 16:52:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774975948; bh=az/tbwwybVECnE/sghykLnICiGoGfPtrsSkbz7HVHT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ip8Nrdl8TrRyvZH3qZfV0KMjFyZ15eg0INvgl+KbOoCPR1Vue4FrStehSwUxe/htY TBlhA12SYevoDfTHH3SppqsT+77IdG3LnyJVIZfHmp7qsASzJzuW1fhHHeyGnk4qb5 zcz2YwJIkGPwdbv4MvOuFzhmjXojH+djK0w5rZX8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sanman Pradhan , Guenter Roeck Subject: [PATCH 6.12 149/244] hwmon: (pmbus/isl68137) Add mutex protection for AVS enable sysfs attributes Date: Tue, 31 Mar 2026 18:21:39 +0200 Message-ID: <20260331161747.267289817@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161741.651718120@linuxfoundation.org> References: <20260331161741.651718120@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sanman Pradhan commit 3075a3951f7708da5a8ab47b0b7d068a32f69e58 upstream. The custom avs0_enable and avs1_enable sysfs attributes access PMBus registers through the exported API helpers (pmbus_read_byte_data, pmbus_read_word_data, pmbus_write_word_data, pmbus_update_byte_data) without holding the PMBus update_lock mutex. These exported helpers do not acquire the mutex internally, unlike the core's internal callers which hold the lock before invoking them. The store callback is especially vulnerable: it performs a multi-step read-modify-write sequence (read VOUT_COMMAND, write VOUT_COMMAND, then update OPERATION) where concurrent access from another thread could interleave and corrupt the register state. Add pmbus_lock_interruptible()/pmbus_unlock() around both the show and store callbacks to serialize PMBus register access with the rest of the driver. Fixes: 038a9c3d1e424 ("hwmon: (pmbus/isl68137) Add driver for Intersil ISL68137 PWM Controller") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan Link: https://lore.kernel.org/r/20260319173055.125271-3-sanman.pradhan@hpe.com Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/pmbus/isl68137.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) --- a/drivers/hwmon/pmbus/isl68137.c +++ b/drivers/hwmon/pmbus/isl68137.c @@ -78,7 +78,15 @@ static ssize_t isl68137_avs_enable_show_ int page, char *buf) { - int val = pmbus_read_byte_data(client, page, PMBUS_OPERATION); + int val; + + val = pmbus_lock_interruptible(client); + if (val) + return val; + + val = pmbus_read_byte_data(client, page, PMBUS_OPERATION); + + pmbus_unlock(client); if (val < 0) return val; @@ -100,6 +108,10 @@ static ssize_t isl68137_avs_enable_store op_val = result ? ISL68137_VOUT_AVS : 0; + rc = pmbus_lock_interruptible(client); + if (rc) + return rc; + /* * Writes to VOUT setpoint over AVSBus will persist after the VRM is * switched to PMBus control. Switching back to AVSBus control @@ -111,17 +123,20 @@ static ssize_t isl68137_avs_enable_store rc = pmbus_read_word_data(client, page, 0xff, PMBUS_VOUT_COMMAND); if (rc < 0) - return rc; + goto unlock; rc = pmbus_write_word_data(client, page, PMBUS_VOUT_COMMAND, rc); if (rc < 0) - return rc; + goto unlock; } rc = pmbus_update_byte_data(client, page, PMBUS_OPERATION, ISL68137_VOUT_AVS, op_val); +unlock: + pmbus_unlock(client); + return (rc < 0) ? rc : count; }