strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with direct assignment. strlcpy in this file is used to copy fixed-length strings which can be completely avoided by direct assignment and is safe to do so. strlen() is used to return the length of @tbuf. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@xxxxxxxxx> --- drivers/hwmon/pmbus/max20730.c | 64 +++++++++++++++++++++-------------------- 1 file changed, 33 insertions(+), 31 deletions(-) diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c index 7bcf27995033..f5ba23f0fed5 100644 --- a/drivers/hwmon/pmbus/max20730.c +++ b/drivers/hwmon/pmbus/max20730.c @@ -113,7 +113,8 @@ static ssize_t max20730_debugfs_read(struct file *file, char __user *buf, struct max20730_debugfs_data *psu = to_psu(idxp, idx); const struct pmbus_driver_info *info; const struct max20730_data *data; - char tbuf[DEBUG_FS_DATA_MAX] = { 0 }; + char tbuf[DEBUG_FS_DATA_MAX] = {}; + char *result = tbuf; u16 val; info = pmbus_get_driver_info(psu->client); @@ -148,13 +149,13 @@ static ssize_t max20730_debugfs_read(struct file *file, char __user *buf, >> MAX20730_MFR_DEVSET1_TSTAT_BIT_POS; if (val == 0) - len = strlcpy(tbuf, "2000\n", DEBUG_FS_DATA_MAX); + result = "2000\n"; else if (val == 1) - len = strlcpy(tbuf, "125\n", DEBUG_FS_DATA_MAX); + result = "125\n"; else if (val == 2) - len = strlcpy(tbuf, "62.5\n", DEBUG_FS_DATA_MAX); + result = "62.5\n"; else - len = strlcpy(tbuf, "32\n", DEBUG_FS_DATA_MAX); + result = "32\n"; break; case MAX20730_DEBUGFS_INTERNAL_GAIN: val = (data->mfr_devset1 & MAX20730_MFR_DEVSET1_RGAIN_MASK) @@ -163,35 +164,35 @@ static ssize_t max20730_debugfs_read(struct file *file, char __user *buf, if (data->id == max20734) { /* AN6209 */ if (val == 0) - len = strlcpy(tbuf, "0.8\n", DEBUG_FS_DATA_MAX); + result = "0.8\n"; else if (val == 1) - len = strlcpy(tbuf, "3.2\n", DEBUG_FS_DATA_MAX); + result = "3.2\n"; else if (val == 2) - len = strlcpy(tbuf, "1.6\n", DEBUG_FS_DATA_MAX); + result = "1.6\n"; else - len = strlcpy(tbuf, "6.4\n", DEBUG_FS_DATA_MAX); + result = "6.4\n"; } else if (data->id == max20730 || data->id == max20710) { /* AN6042 or AN6140 */ if (val == 0) - len = strlcpy(tbuf, "0.9\n", DEBUG_FS_DATA_MAX); + result = "0.9\n"; else if (val == 1) - len = strlcpy(tbuf, "3.6\n", DEBUG_FS_DATA_MAX); + result = "3.6\n"; else if (val == 2) - len = strlcpy(tbuf, "1.8\n", DEBUG_FS_DATA_MAX); + result = "1.8\n"; else - len = strlcpy(tbuf, "7.2\n", DEBUG_FS_DATA_MAX); + result = "7.2\n"; } else if (data->id == max20743) { /* AN6042 */ if (val == 0) - len = strlcpy(tbuf, "0.45\n", DEBUG_FS_DATA_MAX); + result = "0.45\n"; else if (val == 1) - len = strlcpy(tbuf, "1.8\n", DEBUG_FS_DATA_MAX); + result = "1.8\n"; else if (val == 2) - len = strlcpy(tbuf, "0.9\n", DEBUG_FS_DATA_MAX); + result = "0.9\n"; else - len = strlcpy(tbuf, "3.6\n", DEBUG_FS_DATA_MAX); + result = "3.6\n"; } else { - len = strlcpy(tbuf, "Not supported\n", DEBUG_FS_DATA_MAX); + result = "Not supported\n"; } break; case MAX20730_DEBUGFS_BOOT_VOLTAGE: @@ -199,26 +200,26 @@ static ssize_t max20730_debugfs_read(struct file *file, char __user *buf, >> MAX20730_MFR_DEVSET1_VBOOT_BIT_POS; if (val == 0) - len = strlcpy(tbuf, "0.6484\n", DEBUG_FS_DATA_MAX); + result = "0.6484\n"; else if (val == 1) - len = strlcpy(tbuf, "0.8984\n", DEBUG_FS_DATA_MAX); + result = "0.8984\n"; else if (val == 2) - len = strlcpy(tbuf, "1.0\n", DEBUG_FS_DATA_MAX); + result = "1.0\n"; else - len = strlcpy(tbuf, "Invalid\n", DEBUG_FS_DATA_MAX); + result = "Invalid\n"; break; case MAX20730_DEBUGFS_OUT_V_RAMP_RATE: val = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_VRATE) >> MAX20730_MFR_DEVSET2_VRATE_BIT_POS; if (val == 0) - len = strlcpy(tbuf, "4\n", DEBUG_FS_DATA_MAX); + result = "4\n"; else if (val == 1) - len = strlcpy(tbuf, "2\n", DEBUG_FS_DATA_MAX); + result = "2\n"; else if (val == 2) - len = strlcpy(tbuf, "1\n", DEBUG_FS_DATA_MAX); + result = "1\n"; else - len = strlcpy(tbuf, "Invalid\n", DEBUG_FS_DATA_MAX); + result = "Invalid\n"; break; case MAX20730_DEBUGFS_OC_PROTECT_MODE: ret = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_OCPM_MASK) @@ -230,13 +231,13 @@ static ssize_t max20730_debugfs_read(struct file *file, char __user *buf, >> MAX20730_MFR_DEVSET2_SS_BIT_POS; if (val == 0) - len = strlcpy(tbuf, "0.75\n", DEBUG_FS_DATA_MAX); + result = "0.75\n"; else if (val == 1) - len = strlcpy(tbuf, "1.5\n", DEBUG_FS_DATA_MAX); + result = "1.5\n"; else if (val == 2) - len = strlcpy(tbuf, "3\n", DEBUG_FS_DATA_MAX); + result = "3\n"; else - len = strlcpy(tbuf, "6\n", DEBUG_FS_DATA_MAX); + result = "6\n"; break; case MAX20730_DEBUGFS_IMAX: ret = (data->mfr_devset2 & MAX20730_MFR_DEVSET2_IMAX_MASK) @@ -287,9 +288,10 @@ static ssize_t max20730_debugfs_read(struct file *file, char __user *buf, "%d.%d\n", ret / 10000, ret % 10000); break; default: - len = strlcpy(tbuf, "Invalid\n", DEBUG_FS_DATA_MAX); + result = "Invalid\n"; } + len = strlen(result); return simple_read_from_buffer(buf, count, ppos, tbuf, len); } -- 2.41.0.255.g8b1d071c50-goog
