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* FAILED: patch "[PATCH] drm/xe/uapi: Reject coh_none PAT index for CPU_ADDR_MIRROR" failed to apply to 7.1-stable tree
@ 2026-07-29 10:37 gregkh
  2026-07-29 14:46 ` Yao, Jia
  0 siblings, 1 reply; 2+ messages in thread
From: gregkh @ 2026-07-29 10:37 UTC (permalink / raw)
  To: jia.yao, alwin.mathew, matthew.auld, matthew.brost, michal.mrozek,
	shuicheng.lin, stable
  Cc: stable


The patch below does not apply to the 7.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-7.1.y
git checkout FETCH_HEAD
git cherry-pick -x 4d58d7535e826a3175527b6174502f0db319d7f6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026072909-boil-smartness-3be9@gregkh' --subject-prefix 'PATCH 7.1.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4d58d7535e826a3175527b6174502f0db319d7f6 Mon Sep 17 00:00:00 2001
From: Jia Yao <jia.yao@intel.com>
Date: Fri, 17 Apr 2026 05:59:17 +0000
Subject: [PATCH] drm/xe/uapi: Reject coh_none PAT index for CPU_ADDR_MIRROR

Add validation in xe_vm_bind_ioctl() to reject PAT indices
with XE_COH_NONE coherency mode when used with
DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR.

CPU address mirror mappings use system memory that is CPU
cached, which makes them incompatible with COH_NONE PAT
indices. Allowing COH_NONE with CPU cached buffers is a
security risk, as the GPU may bypass CPU caches and read
stale sensitive data from DRAM.

Although CPU_ADDR_MIRROR does not create an immediate
mapping, the backing system memory is still CPU cached.
Apply the same PAT coherency restrictions as
DRM_XE_VM_BIND_OP_MAP_USERPTR.

v2:
- Correct fix tag

v6:
- No change

v7:
- Correct fix tag

v8:
- Rebase

v9:
- Limit the restrictions to iGPU

v10:
- Just add the iGPU logic but keep dGPU logic

Fixes: b43e864af0d4 ("drm/xe/uapi: Add DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR")
Cc: <stable@vger.kernel.org> # v6.15+
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: Mathew Alwin <alwin.mathew@intel.com>
Cc: Michal Mrozek <michal.mrozek@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Jia Yao <jia.yao@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Acked-by: Michal Mrozek <michal.mrozek@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260417055917.2027459-3-jia.yao@intel.com

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 5f4220125c76..c3836f6eab35 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -3658,6 +3658,8 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm,
 				 op == DRM_XE_VM_BIND_OP_MAP_USERPTR) ||
 		    XE_IOCTL_DBG(xe, coh_mode == XE_COH_NONE &&
 				 op == DRM_XE_VM_BIND_OP_MAP_USERPTR) ||
+		    XE_IOCTL_DBG(xe, !IS_DGFX(xe) && coh_mode == XE_COH_NONE &&
+				 is_cpu_addr_mirror) ||
 		    XE_IOCTL_DBG(xe, xe_device_is_l2_flush_optimized(xe) &&
 				 (op == DRM_XE_VM_BIND_OP_MAP_USERPTR ||
 				  is_cpu_addr_mirror) &&


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2026-07-29 10:37 FAILED: patch "[PATCH] drm/xe/uapi: Reject coh_none PAT index for CPU_ADDR_MIRROR" failed to apply to 7.1-stable tree gregkh
2026-07-29 14:46 ` Yao, Jia

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