On Sat, 2021-08-14 at 22:36 +0300, Andy Shevchenko wrote: > On Sat, Aug 14, 2021 at 4:55 PM 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. So, remove all the uses and add > > devm_kstrdup() or devm_kasprintf() instead. > > > > This patch is an effort to clean up the proliferation of str*() > > functions in the kernel and a previous step in the path to remove > > the strcpy function from the kernel entirely [1]. > > > > [1] https://github.com/KSPP/linux/issues/88 > > Thank you very much for doing this! > Now I like the result, > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> [] > > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_magn.c [] > > @@ -261,6 +261,7 @@ int inv_mpu_magn_set_rate(const struct inv_mpu6050_state *st, int fifo_rate) > > */ > > int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st) > > { > > + struct device *dev = regmap_get_device(st->map); > > const char *orient; > > char *str; > > int i; > > @@ -281,19 +282,24 @@ int inv_mpu_magn_set_orient(struct inv_mpu6050_state *st) > > /* z <- -z */ > > 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); > > - if (str == NULL) > > + > > + /* > > + * The value is negated according to one of the following > > + * rules: > > + * > > + * 1) Drop leading minus. > > + * 2) Leave 0 as is. > > + * 3) Add leading minus. > > + */ > > + if (orient[0] == '-') > > + str = devm_kstrdup(dev, orient + 1, GFP_KERNEL); > > + else if (orient[0] == '0' && orient[1] == '\0') bikeshed: I think this change is less intelligible than the original strcmp. And separately, perhaps for loop would be more readable as for (i = 6; i < 9; i++) converting the 6 + i uses to just i. > > + str = devm_kstrdup(dev, orient, GFP_KERNEL); > > + else > > + str = devm_kasprintf(dev, GFP_KERNEL, "-%s", orient); > > + if (!str) > > return -ENOMEM; > > - if (strcmp(orient, "0") == 0) { > > - strcpy(str, orient); > > - } else if (orient[0] == '-') { > > - strcpy(str, &orient[1]); > > - } else { > > - str[0] = '-'; > > - strcpy(&str[1], orient); > > - } > > + > > st->magn_orient.rotation[6 + i] = str; > > } > > break;
