In the Linux kernel, the following vulnerability has been resolved:
wan: wanxl: Only reset hardware after BAR mapping
wanxl_pci_init_one() stores the freshly allocated card in driver data
before the PLX BAR is mapped. Several early probe failures then unwind
through wanxl_pci_remove_one(), including failure to allocate the coherent
status area or to restore the DMA mask.
wanxl_pci_remove_one() unconditionally calls wanxl_reset(), and
wanxl_reset() dereferences card->plx. On those early failures card->plx
is still NULL, so the error path can dereference a NULL MMIO pointer.
Only issue the hardware reset once the BAR mapping exists. The remaining
cleanup in wanxl_pci_remove_one() already checks whether later resources
were allocated.
This issue was found by a static analysis checker and confirmed by
manual source review.