FAILED: patch "[PATCH] KVM: s390: pci: Fix resource leak on IRQ registration failure" failed to apply to 6.18-stable tree

PATCH Applied [email protected] 3 participants 3 messages Aug 5 – Aug 9

Subsystems (3)

Stable branch s390 KVM s390

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[email protected]

author maintainer

2026-08-05 09:35 UTC #0 lore raw

The patch below does not apply to the 6.18-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-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 5580c9858f1e00f60191eb09c3add359836d60b6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026080528-moisten-subheader-b32d@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

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

From 5580c9858f1e00f60191eb09c3add359836d60b6 Mon Sep 17 00:00:00 2001
From: Farhan Ali <[email protected]>
Date: Thu, 23 Jul 2026 15:14:08 -0700
Subject: [PATCH] KVM: s390: pci: Fix resource leak on IRQ registration failure

Currently if kvm_zpci_set_airq() fails, kvm_s390_pci_aif_enable() returns the error code but doesn't do any resource cleanup thus leaking resources. Fix this by cleaning up all the resources such as the GAITE, AIBV, AISB and unpinning any pinned pages. While at it, remove dead code that stored FIB values that were never referenced.

As part of the cleanup, we are also holding the aift_lock a bit longer, as we hold the lock while executing the MPCIFC instruction. Though this is not strictly necessary, it means we don't have to drop and re-acquire in the error case.

Fixes 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")

Cc [email protected]

Reviewed-by Matthew Rosato <[email protected]>

Reviewed-by Christian Borntraeger <[email protected]>

Signed-off-by Farhan Ali <[email protected]>

Tested-by Matthew Rosato <[email protected]>

Signed-off-by Christian Borntraeger <[email protected]>

arch/s390/kvm/pci.c +21 -8

index 1eb127fc9f89..50f495bc8303 100644
@@ -344,19 +344,32 @@ static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib,
 	aift->kzdev[zdev->aisb] = zdev->kzdev;
 	spin_unlock_irq(&aift->gait_lock);
 
-	/* Update guest FIB for re-issue */
-	fib->fmt0.aisbo = zdev->aisb & 63;
-	fib->fmt0.aisb = virt_to_phys(aift->sbv->vector) + (zdev->aisb / 64) * 8;
-	fib->fmt0.isc = gisc;
-
 	/* Save some guest fib values in the host for later use */
-	zdev->kzdev->fib.fmt0.isc = fib->fmt0.isc;
+	zdev->kzdev->fib.fmt0.isc = gisc;
 	zdev->kzdev->fib.fmt0.aibv = fib->fmt0.aibv;
-	mutex_unlock(&aift->aift_lock);
 
 	/* Issue the clp to setup the irq now */
 	rc = kvm_zpci_set_airq(zdev);
-	return rc;
+	if (!rc) {
+		mutex_unlock(&aift->aift_lock);
+		return rc;
+	}
+
+	/* Start cleanup */
+	zdev->kzdev->fib.fmt0.isc = 0;
+	zdev->kzdev->fib.fmt0.aibv = 0;
+
+	spin_lock_irq(&aift->gait_lock);
+	gaite->count--;
+	gaite->aisb = 0;
+	gaite->gisc = 0;
+	gaite->aisbo = 0;
+	gaite->gisa = 0;
+	aift->kzdev[zdev->aisb] = NULL;
+	spin_unlock_irq(&aift->gait_lock);
+
+	airq_iv_release(zdev->aibv);
+	zdev->aibv = NULL;
 
 free_aisb:
 	airq_iv_free_bit(aift->sbv, zdev->aisb);

Farhan Ali

2026-08-07 19:22 UTC #1 lore raw

PATCH 1/1 KVM: s390: pci: Fix resource leak on IRQ registration failure

Fixes 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")

Cc [email protected]

Reviewed-by Matthew Rosato <[email protected]>

Reviewed-by Christian Borntraeger <[email protected]>

Signed-off-by Farhan Ali <[email protected]>

Tested-by Matthew Rosato <[email protected]>

Signed-off-by Christian Borntraeger <[email protected]>

(cherry picked from commit 5580c9858f1e00f60191eb09c3add359836d60b6)

[[email protected]: Resolved merge conflict]

Signed-off-by Farhan Ali <[email protected]>

---
 arch/s390/kvm/pci.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

arch/s390/kvm/pci.c +21 -8

index 20f738fa6556..b8c2d028a8b7 100644
@@ -312,19 +312,32 @@ static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib,
 	aift->kzdev[zdev->aisb] = zdev->kzdev;
 	spin_unlock_irq(&aift->gait_lock);
 
-	/* Update guest FIB for re-issue */
-	fib->fmt0.aisbo = zdev->aisb & 63;
-	fib->fmt0.aisb = virt_to_phys(aift->sbv->vector + (zdev->aisb / 64) * 8);
-	fib->fmt0.isc = gisc;
-
 	/* Save some guest fib values in the host for later use */
-	zdev->kzdev->fib.fmt0.isc = fib->fmt0.isc;
+	zdev->kzdev->fib.fmt0.isc = gisc;
 	zdev->kzdev->fib.fmt0.aibv = fib->fmt0.aibv;
-	mutex_unlock(&aift->aift_lock);
 
 	/* Issue the clp to setup the irq now */
 	rc = kvm_zpci_set_airq(zdev);
-	return rc;
+	if (!rc) {
+		mutex_unlock(&aift->aift_lock);
+		return rc;
+	}
+
+	/* Start cleanup */
+	zdev->kzdev->fib.fmt0.isc = 0;
+	zdev->kzdev->fib.fmt0.aibv = 0;
+
+	spin_lock_irq(&aift->gait_lock);
+	gaite->count--;
+	gaite->aisb = 0;
+	gaite->gisc = 0;
+	gaite->aisbo = 0;
+	gaite->gisa = 0;
+	aift->kzdev[zdev->aisb] = NULL;
+	spin_unlock_irq(&aift->gait_lock);
+
+	airq_iv_release(zdev->aibv);
+	zdev->aibv = NULL;
 
 unlock:
 	mutex_unlock(&aift->aift_lock);

Signature · 1 line

2.43.0

Sasha Levin

maintainer Applied

2026-08-09 03:25 UTC #2 lore raw

Re: [PATCH 6.18.y] KVM: s390: pci: Fix resource leak on IRQ registration failure

Quoted 2 lines · Farhan Ali

Currently if kvm_zpci_set_airq() fails, kvm_s390_pci_aif_enable() returns the error code but doesn't do any resource cleanup thus leaking resources.

Queued for 6.18, thanks.

Signature · 2 lines

Thanks,
Sasha