github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 01:55:51 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

hwmon: adm1275: Prevent reading uninitialized stack

Browse Source 
While adding support for the ROHM BD127X0 hot-swap controllers, sashiko
reported an error in device-name comparison, which can lead to reading
uninitialized stack memory.

Quoting Sashiko:

This is a pre-existing issue, but I noticed that just before this block in
adm1275_probe(), there might be an out-of-bounds stack read:

    ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, block_buffer);
    if (ret < 0) { ... }
    for (mid = adm1275_id; mid->name[0]; mid++) {
            if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
                    break;
    }

Since i2c_smbus_read_block_data() reads up to 32 bytes into the
uninitialized stack array block_buffer without appending a null
terminator, strncasecmp() could read past the valid bytes returned in ret.

For example, if the device returns a shorter string like "adm12", checking
it against "adm1275" up to the length of "adm1275" will continue reading
into uninitialized stack bounds.

Prevent reading uninitialized memory by zeroing the stack array.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: 87102808d0 ("hwmon: (pmbus/adm1275) Validate device ID")
Link: https://lore.kernel.org/r/c8ad38e0cdb347261c6245de2b7965e747f28d22.1782458224.git.mazziesaccount@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Matti Vaittinen 2026-06-26 10:22:04 +03:00 committed by Guenter Roeck
parent ed576f2f4e
commit 553f951781
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/hwmon/pmbus/adm1275.c
View File

@ -512,7 +512,7 @@ static int adm1275_enable_vout_temp(struct adm1275_data *data,
static int adm1275_probe(struct i2c_client *client)
{
s32 (*config_read_fn)(const struct i2c_client *client, u8 reg);
u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1] = {0};
int config, device_config;
int ret;
struct pmbus_driver_info *info;