FAILED: patch "[PATCH] KVM: s390: pci: Fix missing error codes and memory" failed to apply to 6.12-stable tree

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 <[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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x f86842e4d6c482300f4567f492d512c9ccf5bc4f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026080518-tapestry-tartness-3f01@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From f86842e4d6c482300f4567f492d512c9ccf5bc4f Mon Sep 17 00:00:00 2001
From: Farhan Ali <[email protected]>
Date: Thu, 23 Jul 2026 15:14:06 -0700
Subject: [PATCH] KVM: s390: pci: Fix missing error codes and memory
 unaccounting

In kvm_s390_pci_aif_enable() two error paths failed to set an error code,
causing the function to return 0 on failure. It also failed to rollback
memory accounting on failure. Fix both by propagating an error code on
failure and calling unaccount_mem() in the cleanup path.

Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Cc: [email protected]
Reviewed-by: Christian Borntraeger <[email protected]>
Reviewed-by: Matthew Rosato <[email protected]>
Signed-off-by: Farhan Ali <[email protected]>
Tested-by: Matthew Rosato <[email protected]>
Signed-off-by: Christian Borntraeger <[email protected]>

diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index 0741aed442bc..36eb30953bb5 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -300,14 +300,17 @@ static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib,
 	}
 
 	/* Account for pinned pages, roll back on failure */
-	if (account_mem(zdev->kzdev, pcount))
+	rc = account_mem(zdev->kzdev, pcount);
+	if (rc)
 		goto unpin2;
 
 	/* AISB must be allocated before we can fill in GAITE */
 	mutex_lock(&aift->aift_lock);
 	bit = airq_iv_alloc_bit(aift->sbv);
-	if (bit == -1UL)
+	if (bit == -1UL) {
+		rc = -ENOMEM;
 		goto unlock;
+	}
 	zdev->aisb = bit; /* store the summary bit number */
 	zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA |
 				    AIRQ_IV_BITLOCK |
@@ -351,6 +354,8 @@ static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib,
 	return rc;
 
 unlock:
+	if (pcount > 0)
+		unaccount_mem(zdev->kzdev, pcount);
 	mutex_unlock(&aift->aift_lock);
 unpin2:
 	if (fib->fmt0.sum == 1)