| From | Sasha Levin <> | Subject | [PATCH 5.2 066/135] drm/amdgpu: fix a potential information leaking bug | Date | Thu, 22 Aug 2019 13:07:02 -0400 |
| |
From: Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
[ Upstream commit 929e571c04c285861e0bb049a396a2bdaea63282 ]
Coccinelle reports a path that the array "data" is never initialized. The path skips the checks in the conditional branches when either of callback functions, read_wave_vgprs and read_wave_sgprs, is not registered. Later, the uninitialized "data" array is read in the while-loop below and passed to put_user().
Fix the path by allocating the array with kcalloc().
The patch is simplier than adding a fall-back branch that explicitly calls memset(data, 0, ...). Also it does not need the multiplication 1024*sizeof(*data) as the size parameter for memset() though there is no risk of integer overflow.
Signed-off-by: Wang Xiayang <xywang.sjtu@sjtu.edu.cn> Reviewed-by: Chunming Zhou <david1.zhou@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c index 8930d66f22040..91bfb24f963e5 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -703,7 +703,7 @@ static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf, thread = (*pos & GENMASK_ULL(59, 52)) >> 52; bank = (*pos & GENMASK_ULL(61, 60)) >> 60; - data = kmalloc_array(1024, sizeof(*data), GFP_KERNEL); + data = kcalloc(1024, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; -- 2.20.1
|