On Wed, 2022-05-25 at 10:08 +0800, Wang Yufen wrote:
> Resurrect ubsan overflow checks and ubsan report this warning,
> fix it by change the variable [length] type to size_t.
>
> 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
>
> Changes since v1:
> -Change the variable [length] type to unsigned, as Eric Dumazet suggested.
>
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx>
> ---
> include/net/ipv6.h | 4 ++--
> net/ipv6/ip6_output.c | 8 ++++----
> net/ipv6/udp.c | 2 +-
> net/l2tp/l2tp_ip6.c | 2 +-
> 4 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/include/net/ipv6.h b/include/net/ipv6.h
> index 5b38bf1a586b..de9dcc5652c4 100644
> --- a/include/net/ipv6.h
> +++ b/include/net/ipv6.h
> @@ -1063,7 +1063,7 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr);
> int ip6_append_data(struct sock *sk,
> int getfrag(void *from, char *to, int offset, int len,
> int odd, struct sk_buff *skb),
> - void *from, int length, int transhdrlen,
> + void *from, size_t length, int transhdrlen,
> struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
> struct rt6_info *rt, unsigned int flags);
>
> @@ -1079,7 +1079,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk, struct sk_buff_head *queue,
> struct sk_buff *ip6_make_skb(struct sock *sk,
> int getfrag(void *from, char *to, int offset,
> int len, int odd, struct sk_buff *skb),
> - void *from, int length, int transhdrlen,
> + void *from, size_t length, int transhdrlen,
> struct ipcm6_cookie *ipc6,
> struct rt6_info *rt, unsigned int flags,
> struct inet_cork_full *cork);
> diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
> index 4081b12a01ff..7d47ddd1e1f2 100644
> --- a/net/ipv6/ip6_output.c
> +++ b/net/ipv6/ip6_output.c
> @@ -1450,7 +1450,7 @@ static int __ip6_append_data(struct sock *sk,
> struct page_frag *pfrag,
> int getfrag(void *from, char *to, int offset,
> int len, int odd, struct sk_buff *skb),
> - void *from, int length, int transhdrlen,
> + void *from, size_t length, int transhdrlen,
> unsigned int flags, struct ipcm6_cookie *ipc6)
> {
> struct sk_buff *skb, *skb_prev = NULL;
> @@ -1798,7 +1798,7 @@ static int __ip6_append_data(struct sock *sk,
> int ip6_append_data(struct sock *sk,
> int getfrag(void *from, char *to, int offset, int len,
> int odd, struct sk_buff *skb),
> - void *from, int length, int transhdrlen,
> + void *from, size_t length, int transhdrlen,
> struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
> struct rt6_info *rt, unsigned int flags)
> {
> @@ -1995,13 +1995,13 @@ EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);
> struct sk_buff *ip6_make_skb(struct sock *sk,
> int getfrag(void *from, char *to, int offset,
> int len, int odd, struct sk_buff *skb),
> - void *from, int length, int transhdrlen,
> + void *from, size_t length, int transhdrlen,
> struct ipcm6_cookie *ipc6, struct rt6_info *rt,
> unsigned int flags, struct inet_cork_full *cork)
> {
> struct inet6_cork v6_cork;
> struct sk_buff_head queue;
> - int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
> + size_t exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
Is this the above line change needed? Why?
Thanks!
Paolo
