Hi Russell, First bad commit (maybe != root cause): tree: git://git.armlinux.org.uk/~rmk/linux-arm clearfog head: 89b5c2c2bea4a97b0c6254f54d3719fe15c9e38e commit: ee71c167800c79ed367a6cb8d0efb4e2cfffabf7 [2/13] net: dsa: mv88e6xxx: debugfs hacks to fix the compile compiler: sh4-linux-gcc (GCC) 11.2.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; cppcheck possible warnings: (new ones prefixed by >>, may not real problems) ret = sscanf(cmd, "%s %x %x", name, &reg, &val); ^ vim +739 drivers/net/dsa/mv88e6xxx/mv88e6xxx_debugfs.c 3724260d6f3b5e Vivien Didelot 2015-10-22 725 3724260d6f3b5e Vivien Didelot 2015-10-22 726 static ssize_t mv88e6xxx_pvt_write(struct file *file, const char __user *buf, 3724260d6f3b5e Vivien Didelot 2015-10-22 727 size_t count, loff_t *ppos) 3724260d6f3b5e Vivien Didelot 2015-10-22 728 { 3724260d6f3b5e Vivien Didelot 2015-10-22 729 struct seq_file *s = file->private_data; 3724260d6f3b5e Vivien Didelot 2015-10-22 730 struct mv88e6xxx_chip *chip = s->private; 3724260d6f3b5e Vivien Didelot 2015-10-22 731 const u16 mask = (1 << mv88e6xxx_num_ports(chip)) - 1; 3724260d6f3b5e Vivien Didelot 2015-10-22 732 char cmd[32]; 3724260d6f3b5e Vivien Didelot 2015-10-22 733 unsigned int src_dev, src_port, pvlan; 3724260d6f3b5e Vivien Didelot 2015-10-22 734 int ret; 3724260d6f3b5e Vivien Didelot 2015-10-22 735 3724260d6f3b5e Vivien Didelot 2015-10-22 736 if (copy_from_user(cmd, buf, sizeof(cmd))) 3724260d6f3b5e Vivien Didelot 2015-10-22 737 return -EFAULT; 3724260d6f3b5e Vivien Didelot 2015-10-22 738 3724260d6f3b5e Vivien Didelot 2015-10-22 @739 if (sscanf(cmd, "%d %d %x", &src_dev, &src_port, &pvlan) != 3) 3724260d6f3b5e Vivien Didelot 2015-10-22 740 return -EINVAL; 3724260d6f3b5e Vivien Didelot 2015-10-22 741 3724260d6f3b5e Vivien Didelot 2015-10-22 742 if (src_dev >= 32 || src_port >= 16 || pvlan & ~mask) 3724260d6f3b5e Vivien Didelot 2015-10-22 743 return -ERANGE; 3724260d6f3b5e Vivien Didelot 2015-10-22 744 3724260d6f3b5e Vivien Didelot 2015-10-22 745 mutex_lock(&chip->reg_lock); 3724260d6f3b5e Vivien Didelot 2015-10-22 746 ret = _mv88e6xxx_pvt_write(chip, src_dev, src_port, pvlan); 3724260d6f3b5e Vivien Didelot 2015-10-22 747 mutex_unlock(&chip->reg_lock); 3724260d6f3b5e Vivien Didelot 2015-10-22 748 3724260d6f3b5e Vivien Didelot 2015-10-22 749 return ret < 0 ? ret : count; 3724260d6f3b5e Vivien Didelot 2015-10-22 750 } 3724260d6f3b5e Vivien Didelot 2015-10-22 751 :::::: The code at line 739 was first introduced by commit :::::: 3724260d6f3b5e821ce7ead6410416bf02c3fff6 net: dsa: mv88e6xxx: add debugfs interface :::::: TO: Vivien Didelot <vivien.didelot(a)savoirfairelinux.com&gt; :::::: CC: Russell King (Oracle) <rmk+kernel(a)armlinux.org.uk&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org