[PATCH][next] drm/amdgpu: Fix potential integer overflow on shift of a int

From: Colin Ian King
Date: Thu Oct 10 2024 - 07:22:18 EST


The left shift of int 32 bit integer constant 1 is evaluated using 32 bit
arithmetic and then assigned to and operated upon using a 64 bit unsigned
integer. In the case where the shift is 32 or more this can lead to an
overflow. Avoid this by shifting using the BIT_ULL macro instead.

Fixes: f0b19b84d391 ("drm/amdgpu: add amdgpu_jpeg_sched_mask debugfs")
Signed-off-by: Colin Ian King <colin.i.king@xxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
index 95e2796919fc..136a0c8d8c7a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_jpeg.c
@@ -357,14 +357,14 @@ static int amdgpu_debugfs_jpeg_sched_mask_set(void *data, u64 val)
if (!adev)
return -ENODEV;

- mask = (1 << (adev->jpeg.num_jpeg_inst * adev->jpeg.num_jpeg_rings)) - 1;
+ mask = (BIT_ULL(adev->jpeg.num_jpeg_inst * adev->jpeg.num_jpeg_rings)) - 1;
if ((val & mask) == 0)
return -EINVAL;

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 & BIT_ULL((i * adev->jpeg.num_jpeg_rings) + j))
ring->sched.ready = true;
else
ring->sched.ready = false;
@@ -388,7 +388,7 @@ static int amdgpu_debugfs_jpeg_sched_mask_get(void *data, u64 *val)
for (j = 0; j < adev->jpeg.num_jpeg_rings; ++j) {
ring = &adev->jpeg.inst[i].ring_dec[j];
if (ring->sched.ready)
- mask |= 1 << ((i * adev->jpeg.num_jpeg_rings) + j);
+ mask |= BIT_ULL((i * adev->jpeg.num_jpeg_rings) + j);
}
}
*val = mask;
--
2.39.5