[PATCH 6.12.y 2/2] drm/amdgpu: reject CS chunks too large for kvmalloc()

[Sasha Levin <sashal@kernel.org>]

From: Jesse Zhang <Jesse.Zhang@amd.com>

[ Upstream commit ba4c3c202919405f461a393e823e4b72c8518494 ]

The CS ioctl copies every chunk with vmemdup_array_user() before it
looks at it, for whatever length_dw userspace gives. kvmalloc() warns
about allocations above INT_MAX when called without __GFP_NOWARN, so any
process with the render node can trigger a warning. On navi31, a CS with
a chunk of length_dw 0x20000000 returns -ENOMEM after:

  WARNING: mm/slub.c:6841 at __kvmalloc_node_noprof+0x5a5/0x7d0

Reject such chunks with -EINVAL before trying to copy them.

Fixes: 2098105ec65c ("drm: drop drm_[cm]alloc* helpers")
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit dab5f5280406088591645f499f048dcfefab8d7d)
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index bb207ba59e752..c49aabb343a72 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -239,6 +239,12 @@ static int amdgpu_cs_pass1(struct amdgpu_cs_parser *p,
 
 		size = p->chunks[i].length_dw;
 
+		if (size > INT_MAX / sizeof(uint32_t)) {
+			ret = -EINVAL;
+			i--;
+			goto free_partial_kdata;
+		}
+
 		p->chunks[i].kdata = vmemdup_array_user(u64_to_user_ptr(user_chunk.chunk_data),
 							size,
 							sizeof(uint32_t));
-- 
2.53.0