Commit 07e0d99a authored by Chengen Du's avatar Chengen Du Committed by Konrad Rzeszutek Wilk
Browse files

iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic() 



When performing an iSCSI boot using IPv6, iscsistart still reads the
/sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix
length is 64, this causes the shift exponent to become negative,
triggering a UBSAN warning. As the concept of a subnet mask does not
apply to IPv6, the value is set to ~0 to suppress the warning message.

Signed-off-by: default avatarChengen Du <chengen.du@canonical.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent e1e17a17

drivers/firmware/iscsi_ibft.c

+4 −1
Original line number Diff line number Diff line
@@ -310,6 +310,9 @@ static ssize_t ibft_attr_show_nic(void *data, int type, char *buf) 
		str += sprintf_ipaddr(str, nic->ip_addr);

		break;

	case ISCSI_BOOT_ETH_SUBNET_MASK:

		if (nic->subnet_mask_prefix > 32)

			val = cpu_to_be32(~0);

		else

			val = cpu_to_be32(~((1 << (32-nic->subnet_mask_prefix))-1));

		str += sprintf(str, "%pI4", &val);

		break;