[Intel-gfx] [PATCH 8/8] drm/i915/guc: Fix potential invalid pointer dereferences when decoding G2Hs

John.C.Harrison
2022-02-17T23:52:41Z

From: John Harrison <John.C.Harrison@Intel.com>

Some G2H handlers were reading the context id field from the payload
before checking the payload met the minimum length required.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index b70b1ff46418..ea17dca68674 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -3895,12 +3895,13 @@ int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
u32 len)
{
struct intel_context *ce;
- u32 ctx_id = msg[0];
+ u32 ctx_id;

if (unlikely(len < 1)) {
drm_err(&guc_to_gt(guc)->i915->drm, "Invalid length %u\n", len);
return -EPROTO;
}
+ ctx_id = msg[0];

ce = g2h_context_lookup(guc, ctx_id);
if (unlikely(!ce))
@@ -3946,12 +3947,13 @@ int intel_guc_sched_done_process_msg(struct intel_guc *guc,
{
struct intel_context *ce;
unsigned long flags;
- u32 ctx_id = msg[0];
+ u32 ctx_id;

if (unlikely(len < 2)) {
drm_err(&guc_to_gt(guc)->i915->drm, "Invalid length %u\n", len);
return -EPROTO;
}
+ ctx_id = msg[0];

ce = g2h_context_lookup(guc, ctx_id);
if (unlikely(!ce))
--
2.25.1