[PATCH 5.4 283/344] powerpc/sriov: Remove VF eeh_dev state when disabling SR-IOV

Greg Kroah-Hartman
2020-02-21T08:13:35Z

From: Oliver O'Halloran <oohall@gmail.com>

[ Upstream commit 1fb4124ca9d456656a324f1ee29b7bf942f59ac8 ]

When disabling virtual functions on an SR-IOV adapter we currently do not
correctly remove the EEH state for the now-dead virtual functions. When
removing the pci_dn that was created for the VF when SR-IOV was enabled
we free the corresponding eeh_dev without removing it from the child device
list of the eeh_pe that contained it. This can result in crashes due to the
use-after-free.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kernel/pci_dn.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index 9524009ca1ae4..d876eda926094 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -244,9 +244,22 @@ void remove_dev_pci_data(struct pci_dev *pdev)
continue;

#ifdef CONFIG_EEH
- /* Release EEH device for the VF */
+ /*
+ * Release EEH state for this VF. The PCI core
+ * has already torn down the pci_dev for this VF, but
+ * we're responsible to removing the eeh_dev since it
+ * has the same lifetime as the pci_dn that spawned it.
+ */
edev = pdn_to_eeh_dev(pdn);
if (edev) {
+ /*
+ * We allocate pci_dn's for the totalvfs count,
+ * but only only the vfs that were activated
+ * have a configured PE.
+ */
+ if (edev->pe)
+ eeh_rmv_from_parent_pe(edev);
+
pdn->edev = NULL;
kfree(edev);
}
--
2.20.1