We don't need to check the alignment of the offset and there was
potential a buffer overflow as well.
Signed-off-by: Tom St Denis <tom.stdenis at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index c98e59721444..b1ea300008e5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -507,6 +507,9 @@ static ssize_t amdgpu_debugfs_wave_read(struct file *f, char __user *buf,
return result;
}
+// read at most 1024 words
+#define AMDGPU_DEBUGFS_MAX_SGPR_READ 1024
+
static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf,
size_t size, loff_t *pos)
{
@@ -515,7 +518,7 @@ static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf,
ssize_t result = 0;
uint32_t offset, se, sh, cu, wave, simd, thread, bank, *data;
- if (size & 3 || *pos & 3)
+ if (size & 3 || size > (4 * AMDGPU_DEBUGFS_MAX_SGPR_READ))
return -EINVAL;
/* decode offset */
@@ -528,7 +531,8 @@ static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf,
thread = (*pos & GENMASK_ULL(59, 52)) >> 52;
bank = (*pos & GENMASK_ULL(61, 60)) >> 60;
- data = kmalloc_array(1024, sizeof(*data), GFP_KERNEL);
+ data = kmalloc_array(AMDGPU_DEBUGFS_MAX_SGPR_READ, sizeof(*data),
+ GFP_KERNEL);
if (!data)
return -ENOMEM;
--
2.14.3
