[PATCH][next] drm/i915/guc: Use struct_size() helper in kmalloc()

Gustavo A. R. Silva
2022-01-25T18:00:43Z

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.

Also, address the following sparse warnings:
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c:792:23: warning: using sizeof on a flexible structure

Link: https://github.com/KSPP/linux/issues/174
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
index aa6dd6415202..e352a1aad228 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c
@@ -789,7 +789,7 @@ static struct ct_incoming_msg *ct_alloc_msg(u32 num_dwords)
{
struct ct_incoming_msg *msg;

- msg = kmalloc(sizeof(*msg) + sizeof(u32) * num_dwords, GFP_ATOMIC);
+ msg = kmalloc(struct_size(msg, msg, num_dwords), GFP_ATOMIC);
if (msg)
msg->size = num_dwords;
return msg;
--
2.27.0