FAILED: patch "[PATCH] pmdomain: arm: scmi: Fix genpd leak on provider registration" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-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 <[email protected]>.

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-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 7458f72cc28f9eb0de811effcb5376d0ec19094a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025112052-bulldozer-hatbox-e9df@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From 7458f72cc28f9eb0de811effcb5376d0ec19094a Mon Sep 17 00:00:00 2001
From: Sudeep Holla <[email protected]>
Date: Fri, 17 Oct 2025 12:03:20 +0100
Subject: [PATCH] pmdomain: arm: scmi: Fix genpd leak on provider registration
failure

If of_genpd_add_provider_onecell() fails during probe, the previously created generic power domains are not removed, leading to a memory leak and potential kernel crash later in genpd_debug_add().

Add proper error handling to unwind the initialized domains before returning from probe to ensure all resources are correctly released on failure.

Example crash trace observed without this fix:

  | Unable to handle kernel paging request at virtual address fffffffffffffc70
  | CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.0-rc1 #405 PREEMPT
  | Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform
  | pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  | pc : genpd_debug_add+0x2c/0x160
  | lr : genpd_debug_init+0x74/0x98
  | Call trace:
  |  genpd_debug_add+0x2c/0x160 (P)
  |  genpd_debug_init+0x74/0x98
  |  do_one_initcall+0xd0/0x2d8
  |  do_initcall_level+0xa0/0x140
  |  do_initcalls+0x60/0xa8
  |  do_basic_setup+0x28/0x40
  |  kernel_init_freeable+0xe8/0x170
  |  kernel_init+0x2c/0x140
  |  ret_from_fork+0x10/0x20

index 8fe1c0a501c9..b5e2ffd5ea64 100644
@@ -41,7 +41,7 @@ static int scmi_pd_power_off(struct generic_pm_domain *domain)
 
 static int scmi_pm_domain_probe(struct scmi_device *sdev)
 {
-	int num_domains, i;
+	int num_domains, i, ret;
 	struct device *dev = &sdev->dev;
 	struct device_node *np = dev->of_node;
 	struct scmi_pm_domain *scmi_pd;

@@ -108,9 +108,18 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	scmi_pd_data->domains = domains;
 	scmi_pd_data->num_domains = num_domains;
 
+	ret = of_genpd_add_provider_onecell(np, scmi_pd_data);
+	if (ret)
+		goto err_rm_genpds;
+
 	dev_set_drvdata(dev, scmi_pd_data);
 
-	return of_genpd_add_provider_onecell(np, scmi_pd_data);
+	return 0;
+err_rm_genpds:
+	for (i = num_domains - 1; i >= 0; i--)
+		pm_genpd_remove(domains[i]);
+
+	return ret;
 }
 
 static void scmi_pm_domain_remove(struct scmi_device *sdev)

From: Sudeep Holla <[email protected]>

[ Upstream commit 7458f72cc28f9eb0de811effcb5376d0ec19094a ]

If of_genpd_add_provider_onecell() fails during probe, the previously created generic power domains are not removed, leading to a memory leak and potential kernel crash later in genpd_debug_add().

Add proper error handling to unwind the initialized domains before returning from probe to ensure all resources are correctly released on failure.

Example crash trace observed without this fix:

  | Unable to handle kernel paging request at virtual address fffffffffffffc70
  | CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.18.0-rc1 #405 PREEMPT
  | Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform
  | pstate: 00000005 (nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  | pc : genpd_debug_add+0x2c/0x160
  | lr : genpd_debug_init+0x74/0x98
  | Call trace:
  |  genpd_debug_add+0x2c/0x160 (P)
  |  genpd_debug_init+0x74/0x98
  |  do_one_initcall+0xd0/0x2d8
  |  do_initcall_level+0xa0/0x140
  |  do_initcalls+0x60/0xa8
  |  do_basic_setup+0x28/0x40
  |  kernel_init_freeable+0xe8/0x170
  |  kernel_init+0x2c/0x140
  |  ret_from_fork+0x10/0x20

---
 drivers/firmware/arm_scmi/scmi_pm_domain.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

index 0e05a79de82d8..82d923a9d75d7 100644
@@ -54,7 +54,7 @@ static int scmi_pd_power_off(struct generic_pm_domain *domain)
 
 static int scmi_pm_domain_probe(struct scmi_device *sdev)
 {
-	int num_domains, i;
+	int num_domains, i, ret;
 	struct device *dev = &sdev->dev;
 	struct device_node *np = dev->of_node;
 	struct scmi_pm_domain *scmi_pd;

@@ -112,9 +112,18 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	scmi_pd_data->domains = domains;
 	scmi_pd_data->num_domains = num_domains;
 
+	ret = of_genpd_add_provider_onecell(np, scmi_pd_data);
+	if (ret)
+		goto err_rm_genpds;
+
 	dev_set_drvdata(dev, scmi_pd_data);
 
-	return of_genpd_add_provider_onecell(np, scmi_pd_data);
+	return 0;
+err_rm_genpds:
+	for (i = num_domains - 1; i >= 0; i--)
+		pm_genpd_remove(domains[i]);
+
+	return ret;
 }
 
 static void scmi_pm_domain_remove(struct scmi_device *sdev)

2.51.0