[PATCH 7.3.y] PCI/AER: Fix memory leak in aer_recover_work_func() when pci_dev is missing

[Sasha Levin <sashal@kernel.org>]

From: Priyank Rathod <rathodpriyank@google.com>

[ Upstream commit d4c842c3af5bc52b3ca0b8a7f116114e43b6ba44 ]

When ACPI APEI/GHES processes PCIe AER error records, it allocates memory
for aer_capability_regs (entry.regs) from ghes_estatus_pool and queues the
entry into aer_recover_ring.

In aer_recover_work_func(), items are popped from aer_recover_ring via
kfifo_get(). If pci_get_domain_bus_and_slot() fails to find a matching
pci_dev, the code previously executed 'continue', bypassing the call to
ghes_estatus_pool_region_free(). As a result, the memory allocated for
entry.regs from ghes_estatus_pool was leaked.

This is reachable whenever the device reported by firmware is not (or is no
longer) present in the PCI device tree, e.g. after hot-removal or when
firmware reports an error for a device the kernel never enumerated.

Refactor aer_recover_work_func() to ensure ghes_estatus_pool_region_free()
is called unconditionally for every dequeued entry, releasing the pool
memory even when pci_dev is missing.

Fixes: e2abc47a5a1a ("ACPI: APEI: Fix AER info corruption when error status data has multiple sections")
Signed-off-by: Priyank Rathod <rathodpriyank@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260928-b4-fix-aer-memleaks-v5-2-ba6b94c9c9a6@google.com
[ sashal: Combined the upstream pdev recovery guard with the existing err check to preserve false-alarm filtering. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/pcie/aer.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index be332d3f106cb..490f096cfe91c 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1369,14 +1369,13 @@ static void aer_recover_work_func(struct work_struct *work)
 	while (kfifo_get(&aer_recover_ring, &entry)) {
 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
 						   entry.devfn);
-		if (!pdev) {
+		if (!pdev)
 			pr_err_ratelimited("%04x:%02x:%02x.%x: no pci_dev found\n",
 					   entry.domain, entry.bus,
 					   PCI_SLOT(entry.devfn),
 					   PCI_FUNC(entry.devfn));
-			continue;
-		}
-		pci_print_aer(pdev, entry.severity, entry.regs);
+		else
+			pci_print_aer(pdev, entry.severity, entry.regs);
 
 		regs = entry.regs;
 		if (entry.severity == AER_CORRECTABLE)
@@ -1394,7 +1393,7 @@ static void aer_recover_work_func(struct work_struct *work)
 		ghes_estatus_pool_region_free((unsigned long)entry.regs,
 					    sizeof(struct aer_capability_regs));
 
-		if (err) {
+		if (pdev && err) {
 			if (entry.severity == AER_NONFATAL)
 				pcie_do_recovery(pdev, pci_channel_io_normal,
 						 aer_root_reset);
-- 
2.53.0