Hi, On Mon, 12 Jul 2021 at 09:49, YueHaibing <yuehaibing@xxxxxxxxxx> wrote: > > We got this UBSAN warning: > > UBSAN: shift-out-of-bounds in net/ieee802154/nl802154.c:920:44 > shift exponent -1 is negative > CPU: 3 PID: 8258 Comm: repro Not tainted 5.13.0+ #222 > Call Trace: > dump_stack_lvl+0x8d/0xcf > ubsan_epilogue+0xa/0x4e > __ubsan_handle_shift_out_of_bounds+0x161/0x182 > nl802154_new_interface+0x3bf/0x3d0 > genl_family_rcv_msg_doit.isra.15+0x12d/0x170 > genl_rcv_msg+0x11a/0x240 > netlink_rcv_skb+0x69/0x160 > genl_rcv+0x24/0x40 > > NL802154_IFTYPE_UNSPEC is -1, so enum nl802154_iftype type now > is a signed integer, which is assigned by nla_get_u32 in > nl802154_new_interface(), this may cause type is negative and trigger > this warning. I think this is not the right fix, the fix is to change the UAPI that NL802154_IFTYPE_UNSPEC fits into the netlink range of U32. I will prepare a fix for that, it should still be backwards compatible. - Alex
