[PATCH 6.12 091/567] drm/xe/oa: Limit num_syncs to prevent oversized allocations

Greg Kroah-Hartman
2026-01-06T17:19:18Z

From: Shuicheng Lin <shuicheng.lin@intel.com>

[ Upstream commit f8dd66bfb4e184c71bd26418a00546ebe7f5c17a ]

The OA open parameters did not validate num_syncs, allowing
userspace to pass arbitrarily large values, potentially
leading to excessive allocations.

Add check to ensure that num_syncs does not exceed DRM_XE_MAX_SYNCS,
returning -EINVAL when the limit is violated.

v2: use XE_IOCTL_DBG() and drop duplicated check. (Ashutosh)

Fixes: c8507a25cebd ("drm/xe/oa/uapi: Define and parse OA sync properties")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20251205234715.2476561-6-shuicheng.lin@intel.com
(cherry picked from commit e057b2d2b8d815df3858a87dffafa2af37e5945b)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/xe/xe_oa.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
index d306ed0a0443..5916187cd78f 100644
--- a/drivers/gpu/drm/xe/xe_oa.c
+++ b/drivers/gpu/drm/xe/xe_oa.c
@@ -1200,6 +1200,9 @@ static int xe_oa_set_no_preempt(struct xe_oa *oa, u64 value,
static int xe_oa_set_prop_num_syncs(struct xe_oa *oa, u64 value,
struct xe_oa_open_param *param)
{
+ if (XE_IOCTL_DBG(oa->xe, value > DRM_XE_MAX_SYNCS))
+ return -EINVAL;
+
param->num_syncs = value;
return 0;
}
--
2.51.0