@@ -141,7 +141,6 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
const struct iphdr *iph;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
- unsigned int data_len = 0;
struct ip_tunnel *t;
if (tpi->proto == htons(ETH_P_TEB))
@@ -182,7 +181,6 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return 0;
- data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
break;
case ICMP_REDIRECT:
@@ -190,10 +188,16 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
}
#if IS_ENABLED(CONFIG_IPV6)
- if (tpi->proto == htons(ETH_P_IPV6) &&
- !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
- type, data_len))
- return 0;
+ if (tpi->proto == htons(ETH_P_IPV6)) {
+ unsigned int data_len = 0;
+
+ if (type == ICMP_TIME_EXCEEDED)
+ data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
+
+ if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
+ type, data_len))
+ return 0;
+ }
#endif
if (t->parms.iph.daddr == 0 ||
if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled: net/ipv4/ip_gre.c: In function ‘ipgre_err’: net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable] 144 | unsigned int data_len = 0; | ^~~~~~~~ Fix this by moving all data_len processing inside the IPV6-only section that uses its result. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/ Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Simon Horman <horms@kernel.org> --- v3: - Add Reviewed-by, v2: - Do not use the ternary operator, - Target net-next. --- net/ipv4/ip_gre.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)