From: Colin Ian King colin.king@canonical.com
The ring_id maximum boundary is being compared using the > operator instead of >=, leading to an off-by-one error and an out of bounds write into array vgpu->hws_pga[]. Fix this by simply using the correct comparison operator. Also re-work another comparison that uses the comparison > I915_NUM_ENGINES - 1 to use the >= idiom using to keep this consistent in this code.
Detected by CoverityScan, CID#1462404 ("Out-of-bounds write")
Fixes: a2ae95af9646 ("drm/i915/gvt: update CSB and CSB write pointer in virtual HWSP") Signed-off-by: Colin Ian King colin.king@canonical.com --- drivers/gpu/drm/i915/gvt/handlers.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c index 7354ed816f92..c982867e7c2b 100644 --- a/drivers/gpu/drm/i915/gvt/handlers.c +++ b/drivers/gpu/drm/i915/gvt/handlers.c @@ -1398,7 +1398,7 @@ static int hws_pga_write(struct intel_vgpu *vgpu, unsigned int offset, * update the VM CSB status correctly. Here listed registers can * support BDW, SKL or other platforms with same HWSP registers. */ - if (unlikely(ring_id < 0 || ring_id > I915_NUM_ENGINES)) { + if (unlikely(ring_id < 0 || ring_id >= I915_NUM_ENGINES)) { gvt_vgpu_err("VM(%d) access unknown hardware status page register:0x%x\n", vgpu->id, offset); return -EINVAL; @@ -1473,7 +1473,7 @@ static int elsp_mmio_write(struct intel_vgpu *vgpu, unsigned int offset, u32 data = *(u32 *)p_data; int ret = 0;
- if (WARN_ON(ring_id < 0 || ring_id > I915_NUM_ENGINES - 1)) + if (WARN_ON(ring_id < 0 || ring_id >= I915_NUM_ENGINES)) return -EINVAL;
execlist = &vgpu->submission.execlist[ring_id];