From: Tuo Li <islituo@gmail.com>
To: alexander.deucher@amd.com, christian.koenig@amd.com,
Xinhui.Pan@amd.com, airlied@linux.ie, daniel@ffwll.ch,
luben.tuikov@amd.com, tzimmermann@suse.de, sam@ravnborg.org
Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, baijiaju1990@gmail.com,
Tuo Li <islituo@gmail.com>, TOTE Robot <oslab@tsinghua.edu.cn>
Subject: [PATCH] gpu: drm: amd: amdgpu: amdgpu_i2c: fix possible uninitialized-variable access in amdgpu_i2c_router_select_ddc_port()
Date: Wed, 11 Aug 2021 04:34:58 -0700 [thread overview]
Message-ID: <20210811113458.6940-1-islituo@gmail.com> (raw)
The variable val is declared without initialization, and its address is
passed to amdgpu_i2c_get_byte(). In this function, the value of val is
accessed in:
DRM_DEBUG("i2c 0x%02x 0x%02x read failed\n",
addr, *val);
Also, when amdgpu_i2c_get_byte() returns, val may remain uninitialized,
but it is accessed in:
val &= ~amdgpu_connector->router.ddc_mux_control_pin;
To fix this possible uninitialized-variable access, initialize val to 0 in
amdgpu_i2c_router_select_ddc_port().
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c
index bca4dddd5a15..82608df43396 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c
@@ -339,7 +339,7 @@ static void amdgpu_i2c_put_byte(struct amdgpu_i2c_chan *i2c_bus,
void
amdgpu_i2c_router_select_ddc_port(const struct amdgpu_connector *amdgpu_connector)
{
- u8 val;
+ u8 val = 0;
if (!amdgpu_connector->router.ddc_valid)
return;
--
2.25.1
next reply other threads:[~2021-08-11 11:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 11:34 Tuo Li [this message]
2021-08-11 20:15 ` [PATCH] gpu: drm: amd: amdgpu: amdgpu_i2c: fix possible uninitialized-variable access in amdgpu_i2c_router_select_ddc_port() Alex Deucher
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