On Sun, 1 Aug 2021 19:11:57 +0200 Len Baker <len.baker@xxxxxxx> wrote: > strcpy() performs no bounds checking on the destination buffer. This > could result in linear overflows beyond the end of the buffer, leading > to all kinds of misbehaviors. The safe replacement is strscpy(). > > Signed-off-by: Len Baker <len.baker@xxxxxxx> Hi Len, I'm not convinced this is terribly useful in this particular case. As the code stands today, it is easy to verify that the buffer is large enough by looking up a few lines. As you need to do that anyway to check that n, n -1 in the strscpy is correct, what do we gain? I don't mind this if it's part of a general removal of strcpy(), but if so the patch description should state that. Jonathan > --- > This is a task of the KSPP [1] > > [1] https://github.com/KSPP/linux/issues/88 > > drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c > index f282e9cc34c5..3a6aa1c4bf6c 100644 > --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c > +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c > @@ -264,6 +264,7 @@ int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st) > const char *orient; > char *str; > int i; > + size_t n; > > /* fill magnetometer orientation */ > switch (st->chip_type) { > @@ -282,17 +283,18 @@ int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st) > for (i = 0; i < 3; ++i) { > orient = st->orientation.rotation[6 + i]; > /* use length + 2 for adding minus sign if needed */ > - str = devm_kzalloc(regmap_get_device(st->map), > - strlen(orient) + 2, GFP_KERNEL); > + n = strlen(orient) + 2; > + str = devm_kzalloc(regmap_get_device(st->map), n, > + GFP_KERNEL); > if (str == NULL) > return -ENOMEM; > if (strcmp(orient, "0") == 0) { > - strcpy(str, orient); > + strscpy(str, orient, n); > } else if (orient[0] == '-') { > - strcpy(str, &orient[1]); > + strscpy(str, &orient[1], n); > } else { > str[0] = '-'; > - strcpy(&str[1], orient); > + strscpy(&str[1], orient, n - 1); > } > st->magn_orient.rotation[6 + i] = str; > } > -- > 2.25.1 >
