From: Abdurrahman Hussain Date: Tue, 19 May 2026 00:52:32 +0000 (-0700) Subject: hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read with pmbus_lock X-Git-Tag: v7.1-rc5~5^2 X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=4e4af55aaca7f6d7673d5f9889ad0529db86a048;p=thirdparty%2Fkernel%2Flinux.git hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read with pmbus_lock adm1266_state_read() backs the sequencer_state debugfs entry and issues an i2c_smbus_read_word_data(client, ADM1266_READ_STATE) against the device without taking pmbus_lock. pmbus_core holds pmbus_lock around its own multi-transaction sequences (notably the "set PAGE, then read paged register" pattern used by hwmon attributes), so an unlocked debugfs reader can land between a PAGE write and the subsequent paged read in another thread. READ_STATE itself is not paged, so it cannot corrupt PAGE in flight, but the same defensive serialisation that applies to the GPIO accessors applies here: any direct device access from outside pmbus_core should be ordered with respect to pmbus_core's own. Take pmbus_lock at the top of adm1266_state_read() via the scope-based guard(). Fixes: ed1ff457e187 ("hwmon: (pmbus/adm1266) add debugfs for states") Cc: stable@vger.kernel.org Signed-off-by: Abdurrahman Hussain Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-8-e425e4f88139@nexthop.ai Signed-off-by: Guenter Roeck --- diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c index 5ddca57010326..6f6ad7b20e9a9 100644 --- a/drivers/hwmon/pmbus/adm1266.c +++ b/drivers/hwmon/pmbus/adm1266.c @@ -335,6 +335,7 @@ static int adm1266_state_read(struct seq_file *s, void *pdata) struct i2c_client *client = to_i2c_client(dev); int ret; + guard(pmbus_lock)(client); ret = i2c_smbus_read_word_data(client, ADM1266_READ_STATE); if (ret < 0) return ret;