Add proper cleanup when virtfn setup fails to prevent NULL pointer
dereference during device removal. The kernel oops[1] occurred due to
Incorrect error handling flow when pci_setup_device() fails.
Fix it by properly cleaning up virtfn resources when pci_setup_device()
fails, instead of invoking pci_stop_and_remove_bus_device().
This prevents accessing partially initialized virtfn devices during
removal.
[1]
BUG: kernel NULL pointer dereference, address: 00000000000000d0
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP
CPU: 22 UID: 0 PID: 1151 Comm: bash Not tainted 6.13.0+ #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:device_del+0x3d/0x3d0
Call Trace:
<TASK>
? __die+0x20/0x60
? page_fault_oops+0x150/0x3e0
? exc_page_fault+0x74/0x130
? asm_exc_page_fault+0x22/0x30
? device_del+0x3d/0x3d0
pci_remove_bus_device+0x7c/0x100
pci_iov_add_virtfn+0xfa/0x200
sriov_enable+0x208/0x420
mlx5_core_sriov_configure+0x6a/0x160 [mlx5_core]
sriov_numvfs_store+0xae/0x1a0
kernfs_fop_write_iter+0x109/0x1a0
vfs_write+0x2c0/0x3e0
ksys_write+0x62/0xd0
do_syscall_64+0x4c/0x100
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fixes: e3f30d563a38 ("PCI: Make pci_destroy_dev() concurrent safe")
CC: Keith Busch <kbusch@xxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Shay Drory <shayd@xxxxxxxxxx>
---
drivers/pci/iov.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 9e4770cdd4d5..3dfcbf10e127 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -314,8 +314,11 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
pci_read_vf_config_common(virtfn);
rc = pci_setup_device(virtfn);
- if (rc)
+ if (rc) {
+ pci_bus_put(virtfn->bus);
+ kfree(virtfn);
goto failed1;
+ }
virtfn->dev.parent = dev->dev.parent;
virtfn->multifunction = 0;
@@ -336,14 +339,15 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
pci_device_add(virtfn, virtfn->bus);
rc = pci_iov_sysfs_link(dev, virtfn, id);
if (rc)
- goto failed1;
+ goto failed2;
pci_bus_add_device(virtfn);
return 0;
-failed1:
+failed2:
pci_stop_and_remove_bus_device(virtfn);
+failed1:
pci_dev_put(dev);
failed0:
virtfn_remove_bus(dev->bus, bus);
--
2.38.1
