drm/amdgpu: Fix NULL dereference in dpm sysfs handlers

NULL dereference occurs when string that is not ended with space or
newline is written to some dpm sysfs interface (for example pp_dpm_sclk).
This happens because strsep replaces the tmp with NULL if the delimiter
is not present in string, which is then dereferenced by tmp[0].

Reproduction example:
sudo sh -c 'echo -n 1 > /sys/class/drm/card0/device/pp_dpm_sclk'

Signed-off-by: Paweł Gronowski <me@woland.xyz>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Paweł Gronowski 2020-07-19 17:54:53 +02:00 committed by Alex Deucher
parent 88bb16ad99
commit 38e0c89a19
1 changed files with 3 additions and 6 deletions

View File

@ -778,8 +778,7 @@ static ssize_t amdgpu_set_pp_od_clk_voltage(struct device *dev,
tmp_str++;
while (isspace(*++tmp_str));
while (tmp_str[0]) {
sub_str = strsep(&tmp_str, delimiter);
while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {
ret = kstrtol(sub_str, 0, &parameter[parameter_size]);
if (ret)
return -EINVAL;
@ -1039,8 +1038,7 @@ static ssize_t amdgpu_read_mask(const char *buf, size_t count, uint32_t *mask)
memcpy(buf_cpy, buf, bytes);
buf_cpy[bytes] = '\0';
tmp = buf_cpy;
while (tmp[0]) {
sub_str = strsep(&tmp, delimiter);
while ((sub_str = strsep(&tmp, delimiter)) != NULL) {
if (strlen(sub_str)) {
ret = kstrtol(sub_str, 0, &level);
if (ret)
@ -1637,8 +1635,7 @@ static ssize_t amdgpu_set_pp_power_profile_mode(struct device *dev,
i++;
memcpy(buf_cpy, buf, count-i);
tmp_str = buf_cpy;
while (tmp_str[0]) {
sub_str = strsep(&tmp_str, delimiter);
while ((sub_str = strsep(&tmp_str, delimiter)) != NULL) {
ret = kstrtol(sub_str, 0, &parameter[parameter_size]);
if (ret)
return -EINVAL;