5.15-stable review patch. If anyone has any objections, please let me know.
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From: Justin Stitt justinstitt@google.com
[ Upstream commit b0009b8bed98bd5d59449af48781703df261c247 ]
strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces.
We expect bdi->model_name to be NUL-terminated based on its usage with sysfs_emit and format strings:
val->strval is assigned to bdi->model_name in bq24190_charger_get_property(): 1186 | val->strval = bdi->model_name;
... then in power_supply_sysfs.c we use value.strval with a format string: 311 | ret = sysfs_emit(buf, "%s\n", value.strval);
we assigned value.strval via: 285 | ret = power_supply_get_property(psy, psp, &value); ... which invokes psy->desc->get_property(): 1210 | return psy->desc->get_property(psy, psp, val);
with bq24190_charger_get_property(): 1320 | static const struct power_supply_desc bq24190_charger_desc = { ... 1325 | .get_property = bq24190_charger_get_property,
Moreover, no NUL-padding is required as bdi is zero-allocated in bq24190_charger.c: 1798 | bdi = devm_kzalloc(dev, sizeof(*bdi), GFP_KERNEL);
Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nu... [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt justinstitt@google.com Reviewed-by: Kees Cook keescook@chromium.org Link: https://lore.kernel.org/r/20231020-strncpy-drivers-power-supply-bq24190_char... Signed-off-by: Sebastian Reichel sebastian.reichel@collabora.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/power/supply/bq24190_charger.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/power/supply/bq24190_charger.c b/drivers/power/supply/bq24190_charger.c index 90ac5e59a5d6f..8a4729ee1ab19 100644 --- a/drivers/power/supply/bq24190_charger.c +++ b/drivers/power/supply/bq24190_charger.c @@ -1727,7 +1727,7 @@ static int bq24190_probe(struct i2c_client *client,
bdi->client = client; bdi->dev = dev; - strncpy(bdi->model_name, id->name, I2C_NAME_SIZE); + strscpy(bdi->model_name, id->name, sizeof(bdi->model_name)); mutex_init(&bdi->f_reg_lock); bdi->f_reg = 0; bdi->ss_reg = BQ24190_REG_SS_VBUS_STAT_MASK; /* impossible state */