Re: [PATCH v2] drivers/iio: Remove all strcpy() uses in favor of strscpy()
From: Jonathan Cameron <jic23@kernel.org>
Date: 2021-08-08 16:22:18
Also in:
linux-hardening, lkml
On Sat, 7 Aug 2021 17:22:25 +0200 Len Baker [off-list ref] 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(). 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 Signed-off-by: Len Baker <redacted>
Applied to the togreg branch of iio.git and pushed out as testing so 0-day can poke at it and see if we missed anything. Thanks, Jonathan
quoted hunk ↗ jump to hunk
--- Changelog v1 -> v2 - Modify the commit changelog to inform that the motivation of this patch is to remove the strcpy() function from the kernel entirely (Jonathan Cameron). 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