Lyude Paul
2018-Jul-31 01:03 UTC
[Nouveau] [PATCH] drm/nouveau: Fix potential memory access error in nouveau_debugfs_pstate_get()
nouveau_debugfs(drm) will never be NULL, because we're taking the value
of the potentially null device pointer and adding to it so it isn't 0x0.
So, check if drm is NULL instead.
Signed-off-by: Lyude Paul <lyude at redhat.com>
Cc: Karol Herbst <karolherbst at gmail.com>
---
drivers/gpu/drm/nouveau/nouveau_debugfs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_debugfs.c
b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
index 963a4dba8213..d83313c02913 100644
--- a/drivers/gpu/drm/nouveau/nouveau_debugfs.c
+++ b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
@@ -50,13 +50,14 @@ static int
nouveau_debugfs_pstate_get(struct seq_file *m, void *data)
{
struct drm_device *drm = m->private;
- struct nouveau_debugfs *debugfs = nouveau_debugfs(drm);
+ struct nouveau_debugfs *debugfs;
struct nvif_object *ctrl = &debugfs->ctrl;
struct nvif_control_pstate_info_v0 info = {};
int ret, i;
- if (!debugfs)
+ if (!drm)
return -ENODEV;
+ debugfs = nouveau_debugfs(drm);
ret = nvif_mthd(ctrl, NVIF_CONTROL_PSTATE_INFO, &info, sizeof(info));
if (ret)
--
2.17.1
kbuild test robot
2018-Aug-01 09:13 UTC
[Nouveau] [PATCH] drm/nouveau: Fix potential memory access error in nouveau_debugfs_pstate_get()
Hi Lyude,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.18-rc7 next-20180731]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/Lyude-Paul/drm-nouveau-Fix-potential-memory-access-error-in-nouveau_debugfs_pstate_get/20180801-155246
config: i386-randconfig-a1-201830 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.4-2) 4.9.4
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All warnings (new ones prefixed by >>):
drivers/gpu//drm/nouveau/nouveau_debugfs.c: In function
'nouveau_debugfs_pstate_get':>> drivers/gpu//drm/nouveau/nouveau_debugfs.c:54:22: warning:
'debugfs' is used uninitialized in this function [-Wuninitialized]
struct nvif_object *ctrl = &debugfs->ctrl;
^
vim +/debugfs +54 drivers/gpu//drm/nouveau/nouveau_debugfs.c
33b903e8 Marcin Slusarz 2013-02-08 48
6e9fc177 Karol Herbst 2015-07-30 49 static int
6e9fc177 Karol Herbst 2015-07-30 50 nouveau_debugfs_pstate_get(struct
seq_file *m, void *data)
6e9fc177 Karol Herbst 2015-07-30 51 {
1a54082a Noralf Trønnes 2017-01-26 52 struct drm_device *drm =
m->private;
11a2501e Lyude Paul 2018-07-30 53 struct nouveau_debugfs *debugfs;
6e9fc177 Karol Herbst 2015-07-30 @54 struct nvif_object *ctrl =
&debugfs->ctrl;
6e9fc177 Karol Herbst 2015-07-30 55 struct nvif_control_pstate_info_v0
info = {};
6e9fc177 Karol Herbst 2015-07-30 56 int ret, i;
6e9fc177 Karol Herbst 2015-07-30 57
11a2501e Lyude Paul 2018-07-30 58 if (!drm)
6e9fc177 Karol Herbst 2015-07-30 59 return -ENODEV;
11a2501e Lyude Paul 2018-07-30 60 debugfs = nouveau_debugfs(drm);
6e9fc177 Karol Herbst 2015-07-30 61
6e9fc177 Karol Herbst 2015-07-30 62 ret = nvif_mthd(ctrl,
NVIF_CONTROL_PSTATE_INFO, &info, sizeof(info));
6e9fc177 Karol Herbst 2015-07-30 63 if (ret)
6e9fc177 Karol Herbst 2015-07-30 64 return ret;
6e9fc177 Karol Herbst 2015-07-30 65
6e9fc177 Karol Herbst 2015-07-30 66 for (i = 0; i < info.count + 1;
i++) {
6e9fc177 Karol Herbst 2015-07-30 67 const s32 state = i < info.count ?
i :
6e9fc177 Karol Herbst 2015-07-30 68
NVIF_CONTROL_PSTATE_ATTR_V0_STATE_CURRENT;
6e9fc177 Karol Herbst 2015-07-30 69 struct nvif_control_pstate_attr_v0
attr = {
6e9fc177 Karol Herbst 2015-07-30 70 .state = state,
6e9fc177 Karol Herbst 2015-07-30 71 .index = 0,
6e9fc177 Karol Herbst 2015-07-30 72 };
6e9fc177 Karol Herbst 2015-07-30 73
6e9fc177 Karol Herbst 2015-07-30 74 ret = nvif_mthd(ctrl,
NVIF_CONTROL_PSTATE_ATTR,
6e9fc177 Karol Herbst 2015-07-30 75 &attr, sizeof(attr));
6e9fc177 Karol Herbst 2015-07-30 76 if (ret)
6e9fc177 Karol Herbst 2015-07-30 77 return ret;
6e9fc177 Karol Herbst 2015-07-30 78
6e9fc177 Karol Herbst 2015-07-30 79 if (i < info.count)
6e9fc177 Karol Herbst 2015-07-30 80 seq_printf(m, "%02x:",
attr.state);
6e9fc177 Karol Herbst 2015-07-30 81 else
6e9fc177 Karol Herbst 2015-07-30 82 seq_printf(m, "%s:",
info.pwrsrc == 0 ? "DC" :
6e9fc177 Karol Herbst 2015-07-30 83 info.pwrsrc == 1 ?
"AC" : "--");
6e9fc177 Karol Herbst 2015-07-30 84
6e9fc177 Karol Herbst 2015-07-30 85 attr.index = 0;
6e9fc177 Karol Herbst 2015-07-30 86 do {
6e9fc177 Karol Herbst 2015-07-30 87 attr.state = state;
6e9fc177 Karol Herbst 2015-07-30 88 ret = nvif_mthd(ctrl,
NVIF_CONTROL_PSTATE_ATTR,
6e9fc177 Karol Herbst 2015-07-30 89 &attr, sizeof(attr));
6e9fc177 Karol Herbst 2015-07-30 90 if (ret)
6e9fc177 Karol Herbst 2015-07-30 91 return ret;
6e9fc177 Karol Herbst 2015-07-30 92
6e9fc177 Karol Herbst 2015-07-30 93 seq_printf(m, " %s %d",
attr.name, attr.min);
6e9fc177 Karol Herbst 2015-07-30 94 if (attr.min != attr.max)
6e9fc177 Karol Herbst 2015-07-30 95 seq_printf(m, "-%d",
attr.max);
6e9fc177 Karol Herbst 2015-07-30 96 seq_printf(m, " %s",
attr.unit);
6e9fc177 Karol Herbst 2015-07-30 97 } while (attr.index);
6e9fc177 Karol Herbst 2015-07-30 98
6e9fc177 Karol Herbst 2015-07-30 99 if (state >= 0) {
6e9fc177 Karol Herbst 2015-07-30 100 if (info.ustate_ac == state)
6e9fc177 Karol Herbst 2015-07-30 101 seq_printf(m, " AC");
6e9fc177 Karol Herbst 2015-07-30 102 if (info.ustate_dc == state)
6e9fc177 Karol Herbst 2015-07-30 103 seq_printf(m, " DC");
6e9fc177 Karol Herbst 2015-07-30 104 if (info.pstate == state)
6e9fc177 Karol Herbst 2015-07-30 105 seq_printf(m, " *");
6e9fc177 Karol Herbst 2015-07-30 106 } else {
6e9fc177 Karol Herbst 2015-07-30 107 if (info.ustate_ac < -1)
6e9fc177 Karol Herbst 2015-07-30 108 seq_printf(m, " AC");
6e9fc177 Karol Herbst 2015-07-30 109 if (info.ustate_dc < -1)
6e9fc177 Karol Herbst 2015-07-30 110 seq_printf(m, " DC");
6e9fc177 Karol Herbst 2015-07-30 111 }
6e9fc177 Karol Herbst 2015-07-30 112
6e9fc177 Karol Herbst 2015-07-30 113 seq_printf(m, "\n");
6e9fc177 Karol Herbst 2015-07-30 114 }
6e9fc177 Karol Herbst 2015-07-30 115
6e9fc177 Karol Herbst 2015-07-30 116 return 0;
6e9fc177 Karol Herbst 2015-07-30 117 }
6e9fc177 Karol Herbst 2015-07-30 118
:::::: The code at line 54 was first introduced by commit
:::::: 6e9fc177399f08446293fec7607913fdbc95e191 drm/nouveau/debugfs: add copy of
sysfs pstate interface ported to debugfs
:::::: TO: Karol Herbst <nouveau at karolherbst.de>
:::::: CC: Ben Skeggs <bskeggs at redhat.com>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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