[PATCH] drm/amdgpu: fix shift-out-of-bounds in amdgpu_debugfs_jpeg_sched_mask_set

Jesse.Zhang Jesse.Zhang at amd.com
Mon Aug 25 01:21:16 UTC 2025


Fix a UBSAN shift-out-of-bounds warning in amdgpu_debugfs_jpeg_sched_mask_set
when the shift exponent reaches or exceeds 32 bits. The issue occurred because
a 32-bit integer '1' was being shifted by up to 32 bits, which is undefined
behavior.

Replace '1' with '1ULL' to ensure 64-bit arithmetic, matching the u64 type of
'val' and preventing the shift overflow. This is consistent with the existing
mask calculation that already uses 1ULL.

The error manifested as:
UBSAN: shift-out-of-bounds in drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c:373:17
shift exponent 32 is too large for 32-bit type 'int'
v2: remove debug log

Signed-off-by: Jesse Zhang <Jesse.Zhang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
index 5d5e9ee83a5d..88090adcb24b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
@@ -370,7 +370,7 @@ static int amdgpu_debugfs_jpeg_sched_mask_set(void *data, u64 val)
 	for (i = 0; i < adev->jpeg.num_jpeg_inst; ++i) {
 		for (j = 0; j < adev->jpeg.num_jpeg_rings; ++j) {
 			ring = &adev->jpeg.inst[i].ring_dec[j];
-			if (val & (1 << ((i * adev->jpeg.num_jpeg_rings) + j)))
+			if (val & (1ULL << ((i * adev->jpeg.num_jpeg_rings) + j)))
 				ring->sched.ready = true;
 			else
 				ring->sched.ready = false;
-- 
2.49.0



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