4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Niklas Cassel <niklas.cassel@xxxxxxxx> [ Upstream commit 35ad61921f495ee14915d185de79478c1737b4da ] 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> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/endpoint/pci-ep-cfs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/pci/endpoint/pci-ep-cfs.c +++ b/drivers/pci/endpoint/pci-ep-cfs.c @@ -109,7 +109,10 @@ static int pci_epc_epf_link(struct confi goto err_add_epf; 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) + return -EINVAL; + set_bit(func_no, &epc_group->function_num_map); epf->func_no = func_no;