From 487566cb1ccdf3756fdd7bf8d875e612ff3169bb Mon Sep 17 00:00:00 2001 From: Abdurrahman Hussain Date: Fri, 15 May 2026 15:11:50 -0700 Subject: [PATCH] hwmon: (pmbus/adm1266) include PEC byte in pmbus_block_xfer read buffer adm1266_pmbus_block_xfer() sets up the read transaction with .buf = data->read_buf, .len = ADM1266_PMBUS_BLOCK_MAX + 2, but read_buf in struct adm1266_data is declared as u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1]; For a max-length block response (length byte = 255 + up to 1 PEC byte), the i2c controller is told to write 257 bytes into a 256-byte buffer, putting one byte past the end of read_buf. The same response also makes the subsequent PEC compare if (crc != msgs[1].buf[msgs[1].buf[0] + 1]) read a byte beyond the array. Bump the read_buf declaration to ADM1266_PMBUS_BLOCK_MAX + 2 so the buffer can hold the length byte, up to 255 payload bytes, and the PEC byte the i2c_msg length already accounts for. Fixes: 407dc802a9c0 ("hwmon: (pmbus/adm1266) Add Block process call") Cc: stable@vger.kernel.org Signed-off-by: Abdurrahman Hussain Link: https://lore.kernel.org/r/20260515-adm1266-fixes-v1-4-1c1ea1349cfe@nexthop.ai Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/adm1266.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c index 43d9e7407795..5c68e3177f64 100644 --- a/drivers/hwmon/pmbus/adm1266.c +++ b/drivers/hwmon/pmbus/adm1266.c @@ -61,7 +61,7 @@ struct adm1266_data { u8 *dev_mem; struct mutex buf_mutex; u8 write_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned; - u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 1] ____cacheline_aligned; + u8 read_buf[ADM1266_PMBUS_BLOCK_MAX + 2] ____cacheline_aligned; }; static const struct nvmem_cell_info adm1266_nvmem_cells[] = {