From: Ashutosh Dixit Date: Fri, 12 Dec 2025 06:18:48 +0000 (-0800) Subject: drm/xe/oa: Move default oa unit assignment earlier during stream open X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=97e16068d77a036908f69aba35486b21dee17a40;p=thirdparty%2Fkernel%2Flinux.git drm/xe/oa: Move default oa unit assignment earlier during stream open De-referencing param.oa_unit, when an OA unit id is not provided during stream open, results in NPD below. Oops: general protection fault, probably for non-canonical address... KASAN: null-ptr-deref in range... RIP: 0010:xe_oa_stream_open_ioctl+0x169/0x38a0 xe_observation_ioctl+0x19f/0x270 drm_ioctl_kernel+0x1f4/0x410 Fix this by moving default oa unit assignment before the dereference. Reported-by: Peter Senna Tschudin Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6840 Fixes: c7e269aa565f ("drm/xe/oa: Allow exec_queue's to be specified only for OAG OA unit") Signed-off-by: Ashutosh Dixit Reviewed-by: Harish Chegondi Link: https://patch.msgid.link/20251212061850.1565459-2-ashutosh.dixit@intel.com --- diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c index 7dfc59277d6c..d9573cdbcfd2 100644 --- a/drivers/gpu/drm/xe/xe_oa.c +++ b/drivers/gpu/drm/xe/xe_oa.c @@ -1967,10 +1967,6 @@ static int xe_oa_assign_hwe(struct xe_oa *oa, struct xe_oa_open_param *param) enum xe_hw_engine_id id; int ret = 0; - /* If not provided, OA unit defaults to OA unit 0 as per uapi */ - if (!param->oa_unit) - param->oa_unit = &xe_root_mmio_gt(oa->xe)->oa.oa_unit[0]; - /* When we have an exec_q, get hwe from the exec_q */ if (param->exec_q) { param->hwe = xe_gt_hw_engine(param->exec_q->gt, param->exec_q->class, @@ -2036,6 +2032,10 @@ int xe_oa_stream_open_ioctl(struct drm_device *dev, u64 data, struct drm_file *f if (ret) return ret; + /* If not provided, OA unit defaults to OA unit 0 as per uapi */ + if (!param.oa_unit) + param.oa_unit = &xe_root_mmio_gt(oa->xe)->oa.oa_unit[0]; + if (param.exec_queue_id > 0) { /* An exec_queue is only needed for OAR/OAC functionality on OAG */ if (XE_IOCTL_DBG(oa->xe, param.oa_unit->type != DRM_XE_OA_UNIT_TYPE_OAG))