lkml.org 
[lkml]   [2020]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.4 128/138] drm/amdgpu: Fix NULL dereference in dpm sysfs handlers
Date
From: Paweł Gronowski <me@woland.xyz>

commit 38e0c89a19fd13f28d2b4721035160a3e66e270b upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
@@ -691,8 +691,7 @@ static ssize_t amdgpu_set_pp_od_clk_volt
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;
@@ -883,8 +882,7 @@ static ssize_t amdgpu_read_mask(const ch
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)
@@ -1300,8 +1298,7 @@ static ssize_t amdgpu_set_pp_power_profi
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) {
count = -EINVAL;

\
 
 \ /
  Last update: 2020-07-27 16:34    [W:0.926 / U:0.764 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site