From: Wang Xiayang Date: Sat, 27 Jul 2019 09:30:30 +0000 (+0800) Subject: drm/amdgpu: fix a potential information leaking bug X-Git-Tag: v4.19.68~47 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=68340db992f6704b86a27e3f9f91d44ce1c8cb31;p=platform%2Fkernel%2Flinux-rpi.git drm/amdgpu: fix a potential information leaking bug [ 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 Reviewed-by: Chunming Zhou Reviewed-by: Christian König Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c index f5fb937..65cecfd 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;