From 929e571c04c285861e0bb049a396a2bdaea63282 Mon Sep 17 00:00:00 2001 From: Wang Xiayang Date: Sat, 27 Jul 2019 17:30:30 +0800 Subject: [PATCH] drm/amdgpu: fix a potential information leaking bug MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Chunming Zhou Reviewed-by: Christian König Signed-off-by: Alex Deucher --- 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 6d54decef7f8..5652cc72ed3a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -707,7 +707,7 @@ 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