Hi zhanglin, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linux/master] [also build test WARNING on akpm-mm/mm-everything hnaz-mm/master linus/master v5.18-rc6 next-20220509] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/intel-lab-lkp/linux/commits/zhanglin/fs-proc-add-mask_secrets-to-prevent-sensitive-information-leakage/20220509-140823 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c5eb0a61238dd6faf37f58c9ce61c9980aaffd7a config: x86_64-randconfig-r031-20220509 (https://download.01.org/0day-ci/archive/20220510/202205100257.6jjTnf0b-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a385645b470e2d3a1534aae618ea56b31177639f) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/f8d1c429178d1ee0c447ee68f4e7b602c5df911f git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review zhanglin/fs-proc-add-mask_secrets-to-prevent-sensitive-information-leakage/20220509-140823 git checkout f8d1c429178d1ee0c447ee68f4e7b602c5df911f # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/proc/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): fs/proc/mask_secrets.c:71:6: warning: variable 'err' set but not used [-Wunused-but-set-variable] int err = 0; ^ >> fs/proc/mask_secrets.c:49:8: warning: no previous prototype for function 'mask_secrets' [-Wmissing-prototypes] size_t mask_secrets(struct mm_struct *mm, char __user *buf, ^ fs/proc/mask_secrets.c:49:1: note: declare 'static' if the function is not intended to be used outside of this translation unit size_t mask_secrets(struct mm_struct *mm, char __user *buf, ^ static 2 warnings generated. vim +/mask_secrets +49 fs/proc/mask_secrets.c 48 > 49 size_t mask_secrets(struct mm_struct *mm, char __user *buf, 50 size_t count, loff_t pos) 51 { 52 unsigned long arg_start = 0; 53 unsigned long arg_end = 0; 54 int mask_arg_len = 0; 55 size_t remote_vm_copied = 0; 56 struct file *file = 0; 57 struct inode *inode = 0; 58 char *kbuf = 0; 59 char *progname = 0; 60 int proghash = -1; 61 int prog_found = 0; 62 char *mask_arg_start = 0; 63 char *mask_arg_end = 0; 64 struct cmdline_hashtab_item *chi = 0; 65 char *psecret = 0; 66 size_t psecret_len = 0; 67 char *pmask = 0; 68 size_t pmask_len = 0; 69 size_t size; 70 size_t total_copied = 0; 71 int err = 0; 72 73 if (!is_mask_secrets_enabled()) { 74 err = -EPERM; 75 goto exit_err; 76 } 77 78 spin_lock(&mm->arg_lock); 79 arg_start = mm->arg_start; 80 arg_end = mm->arg_end; 81 spin_unlock(&mm->arg_lock); 82 if (arg_start >= arg_end) { 83 err = -ERANGE; 84 goto exit_err; 85 } 86 mask_arg_len = arg_end - arg_start + 1; 87 88 file = get_mm_exe_file(mm); 89 if (!file) { 90 err = -ENOENT; 91 goto exit_err; 92 } 93 inode = file_inode(file); 94 if (!inode) { 95 err = -ENOENT; 96 goto exit_err; 97 } 98 proghash = cmdline_hash(inode->i_ino); 99 kbuf = kzalloc(max(PATH_MAX, mask_arg_len), GFP_KERNEL); 100 if (!kbuf) { 101 err = -ENOMEM; 102 goto exit_err; 103 } 104 progname = d_path(&file->f_path, kbuf, PATH_MAX); 105 if (IS_ERR_OR_NULL(progname)) { 106 err = -ENOENT; 107 goto cleanup_kbuf; 108 } 109 110 rcu_read_lock(); 111 prog_found = 0; 112 hash_for_each_possible_rcu(cmdline_hashtab, chi, hlist, proghash) 113 if (strcmp(chi->progname, progname) == 0) { 114 prog_found = 1; 115 break; 116 } 117 118 if (!prog_found) { 119 rcu_read_unlock(); 120 goto cleanup_kbuf; 121 } 122 123 mask_arg_start = kbuf; 124 mask_arg_end = mask_arg_start + (arg_end - arg_start); 125 remote_vm_copied = access_remote_vm(mm, arg_start, mask_arg_start, mask_arg_len, FOLL_ANON); 126 if (remote_vm_copied <= 0) { 127 rcu_read_unlock(); 128 err = -EIO; 129 goto cleanup_kbuf; 130 } 131 /*skip progname */ 132 for (pmask = mask_arg_start; *pmask && (pmask <= mask_arg_end); pmask++) 133 ; 134 135 if (!chi->secrets) { 136 rcu_read_unlock(); 137 /*mask everything, such as: xxxconnect host port username password.*/ 138 for (pmask = pmask + 1; (pmask <= mask_arg_end); pmask++) 139 for (; (pmask <= mask_arg_end) && (*pmask); pmask++) 140 *pmask = 'Z'; 141 goto copydata; 142 } 143 144 for (pmask = pmask + 1; pmask <= mask_arg_end; pmask++) { 145 psecret = chi->secrets; 146 while (*psecret) { 147 psecret_len = strlen(psecret); 148 if (psecret_len < 2) { 149 rcu_read_unlock(); 150 err = -EINVAL; 151 goto cleanup_kbuf; 152 } 153 154 if (strcmp(pmask, psecret) == 0) { 155 pmask += psecret_len + 1; 156 goto mask_secret; 157 } 158 159 if (strncmp(pmask, psecret, psecret_len) == 0) { 160 /*handle case: --password=xxxx */ 161 if ((psecret[0] == '-') && (psecret[1] == '-')) 162 if (pmask[psecret_len] == '=') { 163 pmask += psecret_len + 1; 164 goto mask_secret; 165 } 166 167 if (psecret[0] == '-') { 168 /*handle case: -password=xxxx or -p=xxxx*/ 169 if (pmask[psecret_len] == '=') { 170 pmask += psecret_len + 1; 171 goto mask_secret; 172 } 173 174 /*handle case: -pxxxx*/ 175 if (psecret_len == 2) { 176 pmask += psecret_len; 177 goto mask_secret; 178 } 179 } 180 } 181 182 if (psecret_len == 2) { 183 pmask_len = strlen(pmask); 184 /*handle case: -yp xxxx, such as: useradd -rp xxxx*/ 185 if ((pmask_len > 2) && (*pmask == '-') 186 && (pmask[pmask_len - 1] == psecret[1])) { 187 pmask += pmask_len + 1; 188 goto mask_secret; 189 } 190 } 191 192 psecret += psecret_len + 1; 193 } 194 195 pmask += strlen(pmask); 196 continue; 197 198 mask_secret: 199 for (; (pmask <= mask_arg_end) && (*pmask); pmask++) 200 *pmask = 'Z'; 201 } 202 rcu_read_unlock(); 203 204 copydata: 205 size = arg_end - pos; 206 size = min_t(size_t, size, count); 207 if (copy_to_user(buf, mask_arg_start + pos - arg_start, size)) 208 goto cleanup_kbuf; 209 210 total_copied = size; 211 212 cleanup_kbuf: 213 kfree(kbuf); 214 215 exit_err: 216 return total_copied; 217 } 218 -- 0-DAY CI Kernel Test Service https://01.org/lkp
