FAILED: patch "[PATCH] drm/amdgpu: free the userptr ranges when a CS fails after" failed to apply to 6.12-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 1b4da805a0ba354a549ce07459c871c17dd94fe0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026102130-uncaring-epilepsy-5ad9@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 1b4da805a0ba354a549ce07459c871c17dd94fe0 Mon Sep 17 00:00:00 2001
From: Jesse Zhang <Jesse.Zhang@amd.com>
Date: Fri, 9 Oct 2026 16:05:05 +0800
Subject: [PATCH] drm/amdgpu: free the userptr ranges when a CS fails after
 parser_bos

amdgpu_cs_parser_bos() allocates an HMM range for every userptr entry of
the BO list and looks up the user pages. Those ranges are only freed when
amdgpu_cs_parser_bos() itself fails or when amdgpu_cs_submit() checks
them under the notifier lock. If amdgpu_cs_patch_jobs(),
amdgpu_cs_vm_handling(), amdgpu_cs_sync_rings() or the early part of
amdgpu_cs_submit() fails, nothing frees them: neither
amdgpu_cs_parser_fini() nor amdgpu_bo_list_free() touch e->range.

Each such CS then leaks the range, its hmm_pfns array (8 bytes per page
of the userptr BO) and the BO reference the range holds. An IB on a ring
that patches the CS in place (e.g. VCN) with an unmapped va_start fails
in amdgpu_cs_patch_ibs() and takes this path.

Free the ranges on those error paths. Ranges amdgpu_cs_submit() already
dropped are NULL, so freeing them again is a no-op.

Fixes: fec8fdb54e8f ("drm/amdgpu: fix userptr HMM range handling v2")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit c52a9542ed7cfd527feb938bd0accada2ac8d267)
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 03b41f803520..ef8a61ce4b1d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -1431,6 +1431,7 @@ static void amdgpu_cs_parser_fini(struct amdgpu_cs_parser *parser)
 int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
 	struct amdgpu_device *adev = drm_to_adev(dev);
+	struct amdgpu_bo_list_entry *e;
 	struct amdgpu_cs_parser parser;
 	int r;
 
@@ -1465,25 +1466,31 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 
 	r = amdgpu_cs_patch_jobs(&parser);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	r = amdgpu_cs_vm_handling(&parser);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	r = amdgpu_cs_sync_rings(&parser);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	trace_amdgpu_cs_ibs(&parser);
 
 	r = amdgpu_cs_submit(&parser, data);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	amdgpu_cs_parser_fini(&parser);
 	return 0;
 
+error_free_user_pages:
+	/* amdgpu_cs_submit() only drops the ranges once it got that far. */
+	amdgpu_bo_list_for_each_userptr_entry(e, parser.bo_list) {
+		amdgpu_hmm_range_free(e->range);
+		e->range = NULL;
+	}
 error_fini:
 	amdgpu_cs_parser_fini(&parser);
 	return r;