tree: https://github.com/0day-ci/linux/commits/UPDATE-20201112-234813/Dmytro-Sh... head: b0c2d7a5f4037f89bed41815642b876706243575 commit: b0c2d7a5f4037f89bed41815642b876706243575 [1/1] net: Variable SLAAC: SLAAC with prefixes of arbitrary length in PIO config: i386-randconfig-m021-20201113 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; New smatch warnings: net/ipv6/addrconf.c:2888 addrconf_prefix_rcv() warn: inconsistent indenting net/ipv6/addrconf.c:2888 addrconf_prefix_rcv() warn: ignoring unreachable code. Old smatch warnings: net/ipv6/addrconf.c:3757 addrconf_notify() error: potential null dereference 'idev'. (ipv6_add_dev returns null) vim +2888 net/ipv6/addrconf.c 2763 2764 void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) 2765 { 2766 struct prefix_info *pinfo; 2767 __u32 valid_lft; 2768 __u32 prefered_lft; 2769 int addr_type, err; 2770 u32 addr_flags = 0; 2771 struct inet6_dev *in6_dev; 2772 struct net *net = dev_net(dev); 2773 2774 pinfo = (struct prefix_info *) opt; 2775 2776 if (len < sizeof(struct prefix_info)) { 2777 netdev_dbg(dev, "addrconf: prefix option too short\n"); 2778 return; 2779 } 2780 2781 /* 2782 * Validation checks ([ADDRCONF], page 19) 2783 */ 2784 2785 addr_type = ipv6_addr_type(&pinfo->prefix); 2786 2787 if (addr_type & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)) 2788 return; 2789 2790 valid_lft = ntohl(pinfo->valid); 2791 prefered_lft = ntohl(pinfo->prefered); 2792 2793 if (prefered_lft > valid_lft) { 2794 net_warn_ratelimited("addrconf: prefix option has invalid lifetime\n"); 2795 return; 2796 } 2797 2798 in6_dev = in6_dev_get(dev); 2799 2800 if (!in6_dev) { 2801 net_dbg_ratelimited("addrconf: device %s not configured\n", 2802 dev->name); 2803 return; 2804 } 2805 2806 /* 2807 * Two things going on here: 2808 * 1) Add routes for on-link prefixes 2809 * 2) Configure prefixes with the auto flag set 2810 */ 2811 2812 if (pinfo->onlink) { 2813 struct fib6_info *rt; 2814 unsigned long rt_expires; 2815 2816 /* Avoid arithmetic overflow. Really, we could 2817 * save rt_expires in seconds, likely valid_lft, 2818 * but it would require division in fib gc, that it 2819 * not good. 2820 */ 2821 if (HZ > USER_HZ) 2822 rt_expires = addrconf_timeout_fixup(valid_lft, HZ); 2823 else 2824 rt_expires = addrconf_timeout_fixup(valid_lft, USER_HZ); 2825 2826 if (addrconf_finite_timeout(rt_expires)) 2827 rt_expires *= HZ; 2828 2829 rt = addrconf_get_prefix_route(&pinfo->prefix, 2830 pinfo->prefix_len, 2831 dev, 2832 RTF_ADDRCONF | RTF_PREFIX_RT, 2833 RTF_DEFAULT, true); 2834 2835 if (rt) { 2836 /* Autoconf prefix route */ 2837 if (valid_lft == 0) { 2838 ip6_del_rt(net, rt, false); 2839 rt = NULL; 2840 } else if (addrconf_finite_timeout(rt_expires)) { 2841 /* not infinity */ 2842 fib6_set_expires(rt, jiffies + rt_expires); 2843 } else { 2844 fib6_clean_expires(rt); 2845 } 2846 } else if (valid_lft) { 2847 clock_t expires = 0; 2848 int flags = RTF_ADDRCONF | RTF_PREFIX_RT; 2849 if (addrconf_finite_timeout(rt_expires)) { 2850 /* not infinity */ 2851 flags |= RTF_EXPIRES; 2852 expires = jiffies_to_clock_t(rt_expires); 2853 } 2854 addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len, 2855 0, dev, expires, flags, 2856 GFP_ATOMIC); 2857 } 2858 fib6_info_release(rt); 2859 } 2860 2861 /* Try to figure out our local address for this prefix */ 2862 2863 if (pinfo->autoconf && in6_dev->cnf.autoconf) { 2864 struct in6_addr addr; 2865 bool tokenized = false, dev_addr_generated = false; 2866 2867 if (pinfo->prefix_len == 64) { 2868 memcpy(&addr, &pinfo->prefix, 8); 2869 2870 if (!ipv6_addr_any(&in6_dev->token)) { 2871 read_lock_bh(&in6_dev->lock); 2872 memcpy(addr.s6_addr + 8, 2873 in6_dev->token.s6_addr + 8, 8); 2874 read_unlock_bh(&in6_dev->lock); 2875 tokenized = true; 2876 } else if (is_addr_mode_generate_stable(in6_dev) && 2877 !ipv6_generate_stable_address(&addr, 0, 2878 in6_dev)) { 2879 addr_flags |= IFA_F_STABLE_PRIVACY; 2880 goto ok; 2881 } else if (ipv6_generate_eui64(addr.s6_addr + 8, dev) && 2882 ipv6_inherit_eui64(addr.s6_addr + 8, in6_dev)) { 2883 goto put; 2884 } else { 2885 dev_addr_generated = true; 2886 } 2887 goto ok; 2889 } else if (((in6_dev->if_flags & IF_RA_VAR_PLEN) == IF_RA_VAR_PLEN) && 2890 pinfo->prefix_len > 0 && pinfo->prefix_len <= 128) { 2891 /* SLAAC with prefixes of arbitrary length (Variable SLAAC). 2892 * draft-mishra-6man-variable-slaac 2893 * draft-mishra-v6ops-variable-slaac-problem-stmt 2894 * Contact: Dmytro Shytyi. 2895 */ 2896 memcpy(&addr, &pinfo->prefix, 16); 2897 if (in6_dev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY) { 2898 if (!ipv6_generate_address_variable_plen(&addr, 2899 0, 2900 in6_dev, 2901 pinfo->prefix_len, 2902 true)) { 2903 addr_flags |= IFA_F_STABLE_PRIVACY; 2904 goto ok; 2905 } 2906 } else if (!ipv6_generate_address_variable_plen(&addr, 2907 0, 2908 in6_dev, 2909 pinfo->prefix_len, 2910 false)) { 2911 goto ok; 2912 } 2913 } else { 2914 net_dbg_ratelimited("IPv6: Prefix with unexpected length %d\n", 2915 pinfo->prefix_len); 2916 } 2917 goto put; 2918 2919 ok: 2920 err = addrconf_prefix_rcv_add_addr(net, dev, pinfo, in6_dev, 2921 &addr, addr_type, 2922 addr_flags, sllao, 2923 tokenized, valid_lft, 2924 prefered_lft); 2925 if (err) 2926 goto put; 2927 2928 /* Ignore error case here because previous prefix add addr was 2929 * successful which will be notified. 2930 */ 2931 ndisc_ops_prefix_rcv_add_addr(net, dev, pinfo, in6_dev, &addr, 2932 addr_type, addr_flags, sllao, 2933 tokenized, valid_lft, 2934 prefered_lft, 2935 dev_addr_generated); 2936 } 2937 inet6_prefix_notify(RTM_NEWPREFIX, in6_dev, pinfo); 2938 put: 2939 in6_dev_put(in6_dev); 2940 } 2941 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org