PCI: Fix NULL dereference in SR-IOV VF creation error path

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: PCI: Fix NULL dereference in SR-IOV VF creation error path Clean up when virtfn setup fails to prevent NULL pointer dereference during device removal. The kernel oops below occurred due to incorrect error handling flow when pci_setup_device() fails. Add pci_iov_scan_device(), which handles virtfn allocation and setup and cleans up if pci_setup_device() fails, so pci_iov_add_virtfn() doesn't need to call pci_stop_and_remove_bus_device(). This prevents accessing partially initialized virtfn devices during removal. BUG: kernel NULL pointer dereference, address: 00000000000000d0 RIP: 0010:device_del+0x3d/0x3d0 Call Trace: 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 [bhelgaas: commit log, return ERR_PTR(-ENOMEM) directly]

References

• https://git.kernel.org/stable/c/ef421b4d206f0d3681804b8f94f06a8458a53aaf
• https://git.kernel.org/stable/c/c67a233834b778b8c78f8b62c072ccf87a9eb6d0
• https://git.kernel.org/stable/c/04d50d953ab46d96b0b32d5ad955fceaa28622db