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 5F4FC3BB48 for ; Mon, 30 Mar 2026 23:46:31 +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=1774914391; cv=none; b=Zx7v5KvebUKAL6i39u/wJQmjGHN+Ic4oiJ146KuDJPFHb2hWW+ewJjNUqZMiNjw845yFjhMP/2Kvs/jUdWxPdM6qfyKPR9uqQ5QFEzN1L8PGQF0JC+b16KoV6Zhmytj1HBrmbzN48C87UQ0z9e3acxp7s6Ds67TJlggN5BG7yxA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774914391; c=relaxed/simple; bh=YNkxkgw+A81nF4QBr9sJU3P/3g6tBrdpovi3ky69D0k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WNItDqD/rHnaC9w+S2IRsqPksVbAj6zeP/YD6gaDw8EHWxVZJbsISZdb2L0igO5EoDeWBLufJ79sutsnfZMSFumqT3zznyjjTWcIeiqCxNdjVU0Bxqt3Y6dK8rQqSLR9Lk/eXEzHS/lV+2GQdAG/S4FBWEAB802pAs6k3vDtDDY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j2/KwagO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="j2/KwagO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A68F6C19423; Mon, 30 Mar 2026 23:46:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774914391; bh=YNkxkgw+A81nF4QBr9sJU3P/3g6tBrdpovi3ky69D0k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j2/KwagO+W1yBMlCSuo/ZSnFMjYTp5OgoLHt3tQGofhjrao6EuNAnB5vcmalLKFRd CXmWoo4UzkdrrgTSt8g3bsuYQ2rjUInWmPRvpDCFYYGdjzEJdbtwdFm0gCZ4gTs4v7 f/MzIQ5En52/ewGIy59kSOOvIMRM3WWlIaRQ8+vjjZNC4LBagHFle/VFyuaima3Ymk i6lc70SbGFHrDKP8H1NQhkTUc2/C+MEVEw0K+OWVeWh1iQqRS9IXV/fhxMWRFSaDlN stGhAmG+KSD8u2mvuU8/Pcyokbovi9nZBTDtMEueEsAsFY6eVEOJ6K/gYmQiSHupmd 8EyJm6mm4gMpQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Sanman Pradhan , Guenter Roeck , Sasha Levin Subject: [PATCH 6.1.y 2/2] hwmon: (pmbus/isl68137) Add mutex protection for AVS enable sysfs attributes Date: Mon, 30 Mar 2026 19:46:28 -0400 Message-ID: <20260330234628.1398011-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260330234628.1398011-1-sashal@kernel.org> References: <2026032920-species-uncrushed-8b38@gregkh> <20260330234628.1398011-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sanman Pradhan [ Upstream commit 3075a3951f7708da5a8ab47b0b7d068a32f69e58 ] 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: Sasha Levin --- drivers/hwmon/pmbus/isl68137.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c index 525238fefc1f1..8ed1f6923ab55 100644 --- a/drivers/hwmon/pmbus/isl68137.c +++ b/drivers/hwmon/pmbus/isl68137.c @@ -78,7 +78,15 @@ static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client, 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_page(struct i2c_client *client, 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_page(struct i2c_client *client, 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; } -- 2.53.0