[PATCH AUTOSEL 4.9 17/80] vfio/pci: fix memory leaks in alloc_perm_bits()

Sasha Levin
2020-06-18T01:31:31Z

From: Qian Cai <cai@lca.pw>

[ Upstream commit 3e63b94b6274324ff2e7d8615df31586de827c4e ]

vfio_pci_disable() calls vfio_config_free() but forgets to call
free_perm_bits() resulting in memory leaks,

unreferenced object 0xc000000c4db2dee0 (size 16):
comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s)
hex dump (first 16 bytes):
00 00 ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................
backtrace:
[<00000000a6a4552d>] alloc_perm_bits+0x58/0xe0 [vfio_pci]
[<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci]
init_pci_cap_msi_perm at drivers/vfio/pci/vfio_pci_config.c:1125
(inlined by) vfio_msi_cap_len at drivers/vfio/pci/vfio_pci_config.c:1180
(inlined by) vfio_cap_len at drivers/vfio/pci/vfio_pci_config.c:1241
(inlined by) vfio_cap_init at drivers/vfio/pci/vfio_pci_config.c:1468
(inlined by) vfio_config_init at drivers/vfio/pci/vfio_pci_config.c:1707
[<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci]
[<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio]
[<000000009e34c54f>] ksys_ioctl+0xd8/0x130
[<000000006577923d>] sys_ioctl+0x28/0x40
[<000000006d7b1cf2>] system_call_exception+0x114/0x1e0
[<0000000008ea7dd5>] system_call_common+0xf0/0x278
unreferenced object 0xc000000c4db2e330 (size 16):
comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s)
hex dump (first 16 bytes):
00 ff ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................
backtrace:
[<000000004c71914f>] alloc_perm_bits+0x44/0xe0 [vfio_pci]
[<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci]
[<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci]
[<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio]
[<000000009e34c54f>] ksys_ioctl+0xd8/0x130
[<000000006577923d>] sys_ioctl+0x28/0x40
[<000000006d7b1cf2>] system_call_exception+0x114/0x1e0
[<0000000008ea7dd5>] system_call_common+0xf0/0x278

Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Signed-off-by: Qian Cai <cai@lca.pw>
[aw: rolled in follow-up patch]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/vfio/pci/vfio_pci_config.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 84905d074c4f..608b94a0ee0e 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -1729,8 +1729,11 @@ void vfio_config_free(struct vfio_pci_device *vdev)
vdev->vconfig = NULL;
kfree(vdev->pci_config_map);
vdev->pci_config_map = NULL;
- kfree(vdev->msi_perm);
- vdev->msi_perm = NULL;
+ if (vdev->msi_perm) {
+ free_perm_bits(vdev->msi_perm);
+ kfree(vdev->msi_perm);
+ vdev->msi_perm = NULL;
+ }
}

/*
--
2.25.1