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* [PATCH] drm/i915/gvt: fix unterminated-string-initialization warning
@ 2025-03-27 12:47 Jani Nikula
  2025-03-27 13:40 ` ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Jani Nikula @ 2025-03-27 12:47 UTC (permalink / raw)
  To: intel-gfx
  Cc: jani.nikula, Kees Cook, Nicolas Chauvet, Damian Tometzki, stable

Initializing const char opregion_signature[16] = OPREGION_SIGNATURE
(which is "IntelGraphicsMem") drops the NUL termination of the
string. This is intentional, but the compiler doesn't know this.

Switch to initializing header->signature directly from the string
litaral, with sizeof destination rather than source. We don't treat the
signature as a string other than for initialization; it's really just a
blob of binary data.

Add a static assert for good measure to cross-check the sizes.

Reported-by: Kees Cook <kees@kernel.org>
Closes: https://lore.kernel.org/r/20250310222355.work.417-kees@kernel.org
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13934
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Tested-by: Damian Tometzki <damian@riscv-rocks.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/i915/gvt/opregion.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/opregion.c b/drivers/gpu/drm/i915/gvt/opregion.c
index 509f9ccae3a9..dbad4d853d3a 100644
--- a/drivers/gpu/drm/i915/gvt/opregion.c
+++ b/drivers/gpu/drm/i915/gvt/opregion.c
@@ -222,7 +222,6 @@ int intel_vgpu_init_opregion(struct intel_vgpu *vgpu)
 	u8 *buf;
 	struct opregion_header *header;
 	struct vbt v;
-	const char opregion_signature[16] = OPREGION_SIGNATURE;
 
 	gvt_dbg_core("init vgpu%d opregion\n", vgpu->id);
 	vgpu_opregion(vgpu)->va = (void *)__get_free_pages(GFP_KERNEL |
@@ -236,8 +235,10 @@ int intel_vgpu_init_opregion(struct intel_vgpu *vgpu)
 	/* emulated opregion with VBT mailbox only */
 	buf = (u8 *)vgpu_opregion(vgpu)->va;
 	header = (struct opregion_header *)buf;
-	memcpy(header->signature, opregion_signature,
-	       sizeof(opregion_signature));
+
+	static_assert(sizeof(header->signature) == sizeof(OPREGION_SIGNATURE) - 1);
+	memcpy(header->signature, OPREGION_SIGNATURE, sizeof(header->signature));
+
 	header->size = 0x8;
 	header->opregion_ver = 0x02000000;
 	header->mboxes = MBOX_VBT;
-- 
2.39.5


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2025-04-01  8:46 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2025-03-27 12:47 [PATCH] drm/i915/gvt: fix unterminated-string-initialization warning Jani Nikula
2025-03-27 13:40 ` ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
2025-03-27 13:58 ` ✓ i915.CI.BAT: success " Patchwork
2025-03-27 16:13 ` ✗ i915.CI.Full: failure " Patchwork
2025-03-30 14:53 ` [PATCH] " Zhenyu Wang
2025-04-01  8:46   ` Jani Nikula

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