find_first_zero_bit()'s parameter 'size' is defined in bits, not in bytes. Calling find_first_zero_bit() with the wrong size unit will lead to insidious bugs. Fix this by calling find_first_zero_bit() with size BITS_PER_LONG, rather than sizeof() and add missing find_first_zero_bit() return handling. Fixes: d74679911610 ("PCI: endpoint: Introduce configfs entry for configuring EP functions") Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> --- drivers/pci/endpoint/pci-ep-cfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c index e1f5adc9e113..f5ccd1aa2963 100644 --- a/drivers/pci/endpoint/pci-ep-cfs.c +++ b/drivers/pci/endpoint/pci-ep-cfs.c @@ -109,7 +109,11 @@ static int pci_epc_epf_link(struct config_item *epc_item, return ret; func_no = find_first_zero_bit(&epc_group->function_num_map, - sizeof(epc_group->function_num_map)); + BITS_PER_LONG); + if (func_no >= BITS_PER_LONG) { + ret = -EINVAL; + goto err_func_no; + } set_bit(func_no, &epc_group->function_num_map); epf->func_no = func_no; @@ -121,6 +125,7 @@ static int pci_epc_epf_link(struct config_item *epc_item, err_epf_bind: clear_bit(func_no, &epc_group->function_num_map); +err_func_no: pci_epc_remove_epf(epc, epf); return ret; -- 2.14.2