Hi Eric, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Eric-Woudstra/netfilter-utils-nf_checksum-_partial-correct-data-networkheader/20250705-031418 base: https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git main patch link: https://lore.kernel.org/r/20250704191135.1815969-2-ericwouds%40gmail.com patch subject: [PATCH v13 nf-next 1/3] netfilter: utils: nf_checksum(_partial) correct data!=networkheader config: x86_64-randconfig-r071-20250706 (https://download.01.org/0day-ci/archive/20250706/202507061710.RCwA4Kjw-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0 If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202507061710.RCwA4Kjw-lkp@xxxxxxxxx/ smatch warnings: net/netfilter/utils.c:131 nf_checksum() warn: signedness bug returning '(-12)' net/netfilter/utils.c:155 nf_checksum_partial() warn: signedness bug returning '(-12)' vim +131 net/netfilter/utils.c ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 123 __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook, ^^^^^^^ ebee5a50d0b7cd Florian Westphal 2018-06-25 124 unsigned int dataoff, u8 protocol, ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 125 unsigned short family) ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 126 { 39644744ee13d9 Eric Woudstra 2025-07-04 127 unsigned int nhpull = skb_network_header(skb) - skb->data; ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 128 __sum16 csum = 0; ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 129 39644744ee13d9 Eric Woudstra 2025-07-04 130 if (!pskb_may_pull(skb, nhpull)) 39644744ee13d9 Eric Woudstra 2025-07-04 @131 return -ENOMEM; This -ENOMEM doesn't work because the return type is u16. 39644744ee13d9 Eric Woudstra 2025-07-04 132 __skb_pull(skb, nhpull); ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 133 switch (family) { ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 134 case AF_INET: 39644744ee13d9 Eric Woudstra 2025-07-04 135 csum = nf_ip_checksum(skb, hook, dataoff - nhpull, protocol); ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 136 break; ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 137 case AF_INET6: 39644744ee13d9 Eric Woudstra 2025-07-04 138 csum = nf_ip6_checksum(skb, hook, dataoff - nhpull, protocol); ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 139 break; ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 140 } 39644744ee13d9 Eric Woudstra 2025-07-04 141 __skb_push(skb, nhpull); ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 142 ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 143 return csum; ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 144 } ef71fe27ec2f16 Pablo Neira Ayuso 2017-11-27 145 EXPORT_SYMBOL_GPL(nf_checksum); f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 146 f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 147 __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook, f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 148 unsigned int dataoff, unsigned int len, ebee5a50d0b7cd Florian Westphal 2018-06-25 149 u8 protocol, unsigned short family) f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 150 { 39644744ee13d9 Eric Woudstra 2025-07-04 151 unsigned int nhpull = skb_network_header(skb) - skb->data; f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 152 __sum16 csum = 0; f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 153 39644744ee13d9 Eric Woudstra 2025-07-04 154 if (!pskb_may_pull(skb, nhpull)) 39644744ee13d9 Eric Woudstra 2025-07-04 @155 return -ENOMEM; Same. 39644744ee13d9 Eric Woudstra 2025-07-04 156 __skb_pull(skb, nhpull); f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 157 switch (family) { f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 158 case AF_INET: 39644744ee13d9 Eric Woudstra 2025-07-04 159 csum = nf_ip_checksum_partial(skb, hook, dataoff - nhpull, 39644744ee13d9 Eric Woudstra 2025-07-04 160 len, protocol); f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 161 break; f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 162 case AF_INET6: 39644744ee13d9 Eric Woudstra 2025-07-04 163 csum = nf_ip6_checksum_partial(skb, hook, dataoff - nhpull, 39644744ee13d9 Eric Woudstra 2025-07-04 164 len, protocol); f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 165 break; f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 166 } 39644744ee13d9 Eric Woudstra 2025-07-04 167 __skb_push(skb, nhpull); f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 168 f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 169 return csum; f7dcbe2f36a660 Pablo Neira Ayuso 2017-12-20 170 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
