3bc955987f ("powerpc/PCI: Use list_for_each_entry() for bus traversal")
caused a NULL pointer dereference because the loop body set the iterator to
NULL:
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc000000000041d78
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c000000000041d78] .sys_pciconfig_iobase+0x68/0x1f0
LR [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0
Call Trace:
[c0000003b4787db0] [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 (unreliable)
[c0000003b4787e30] [c000000000009ed8] syscall_exit+0x0/0x98
Fix it by using a temporary variable for the iterator.
[bhelgaas: changelog, drop tmp_bus initialization]
Fixes: 3bc955987f powerpc/PCI: Use list_for_each_entry() for bus traversal
Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>