| Message ID | 20220524034629.395939-1-wangyufen@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] ipv6: Fix signed integer overflow in __ip6_append_data | expand |
On Mon, May 23, 2022 at 8:29 PM Wang Yufen <wangyufen@huawei.com> wrote: > > Resurrect ubsan overflow checks and ubsan report this warning, > fix it by change len check from INT_MAX to IPV6_MAXPLEN. > > UBSAN: signed-integer-overflow in net/ipv6/ip6_output.c:1489:19 > 2147479552 + 8567 cannot be represented in type 'int' OK, so why not fix this point, instead of UDP, which is only one of the possible callers ? It seems the check in __ip6_append_data() should be unsigned.
在 2022/5/24 11:54, Eric Dumazet 写道: > On Mon, May 23, 2022 at 8:29 PM Wang Yufen <wangyufen@huawei.com> wrote: >> Resurrect ubsan overflow checks and ubsan report this warning, >> fix it by change len check from INT_MAX to IPV6_MAXPLEN. >> >> UBSAN: signed-integer-overflow in net/ipv6/ip6_output.c:1489:19 >> 2147479552 + 8567 cannot be represented in type 'int' > OK, so why not fix this point, instead of UDP, which is only one of > the possible callers ? > > It seems the check in __ip6_append_data() should be unsigned. > . I modified it based on the IPv4 process: udp_sendmsg->ip_append_data->__ip_append_data The other callers may have the same issue, it would be more appropriate to change the variable [length] to size_t in the entire process. I'll try to change it. Thanks.
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 7f0fa9bd9ffe..9cdb8c5f734c 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1368,7 +1368,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) /* Rough check on arithmetic overflow, better check is made in ip6_append_data(). */ - if (len > INT_MAX - sizeof(struct udphdr)) + if (len > IPV6_MAXPLEN) return -EMSGSIZE; getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
Resurrect ubsan overflow checks and ubsan report this warning, fix it by change len check from INT_MAX to IPV6_MAXPLEN. UBSAN: signed-integer-overflow in net/ipv6/ip6_output.c:1489:19 2147479552 + 8567 cannot be represented in type 'int' CPU: 0 PID: 253 Comm: err Not tainted 5.16.0+ #1 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x214/0x230 show_stack+0x30/0x78 dump_stack_lvl+0xf8/0x118 dump_stack+0x18/0x30 ubsan_epilogue+0x18/0x60 handle_overflow+0xd0/0xf0 __ubsan_handle_add_overflow+0x34/0x44 __ip6_append_data.isra.48+0x1598/0x1688 ip6_append_data+0x128/0x260 udpv6_sendmsg+0x680/0xdd0 inet6_sendmsg+0x54/0x90 sock_sendmsg+0x70/0x88 ____sys_sendmsg+0xe8/0x368 ___sys_sendmsg+0x98/0xe0 __sys_sendmmsg+0xf4/0x3b8 __arm64_sys_sendmmsg+0x34/0x48 invoke_syscall+0x64/0x160 el0_svc_common.constprop.4+0x124/0x300 do_el0_svc+0x44/0xc8 el0_svc+0x3c/0x1e8 el0t_64_sync_handler+0x88/0xb0 el0t_64_sync+0x16c/0x170 Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Yufen <wangyufen@huawei.com> --- net/ipv6/udp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)