Hi Markus, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-nonmm-unstable] [also build test WARNING on herbert-crypto-2.6/master herbert-cryptodev-2.6/master linus/master v6.12-rc3 next-20241015] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Markus-Elfring/crypto-lib-mpi-Extend-support-for-scope-based-resource-management/20241012-231156 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-nonmm-unstable patch link: https://lore.kernel.org/r/300a0376-f003-4862-bb16-7e004733c9c1%40web.de patch subject: [PATCH v3 2/3] lib/digsig: Use scope-based resource management for two MPI variables in digsig_verify_rsa() config: arm-randconfig-002-20241016 (https://download.01.org/0day-ci/archive/20241016/202410160438.SOIZeFku-lkp@xxxxxxxxx/config) compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 70e0a7e7e6a8541bcc46908c592eed561850e416) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241016/202410160438.SOIZeFku-lkp@xxxxxxxxx/reproduce) 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> | Closes: https://lore.kernel.org/oe-kbuild-all/202410160438.SOIZeFku-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from lib/digsig.c:25: In file included from include/linux/mpi.h:21: In file included from include/linux/scatterlist.h:8: In file included from include/linux/mm.h:2213: include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion] 518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_" | ~~~~~~~~~~~ ^ ~~~ >> lib/digsig.c:176:3: warning: label at end of compound statement is a C23 extension [-Wc23-extensions] 176 | } | ^ lib/digsig.c:178:2: warning: label at end of compound statement is a C23 extension [-Wc23-extensions] 178 | } | ^ 3 warnings generated. vim +176 lib/digsig.c 16 17 #include <linux/err.h> 18 #include <linux/module.h> 19 #include <linux/slab.h> 20 #include <linux/key.h> 21 #include <linux/crypto.h> 22 #include <crypto/hash.h> 23 #include <crypto/sha1.h> 24 #include <keys/user-type.h> > 25 #include <linux/mpi.h> 26 #include <linux/digsig.h> 27 28 static struct crypto_shash *shash; 29 30 static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg, 31 unsigned long msglen, 32 unsigned long modulus_bitlen, 33 unsigned long *outlen) 34 { 35 unsigned long modulus_len, ps_len, i; 36 37 modulus_len = (modulus_bitlen >> 3) + (modulus_bitlen & 7 ? 1 : 0); 38 39 /* test message size */ 40 if ((msglen > modulus_len) || (modulus_len < 11)) 41 return NULL; 42 43 /* separate encoded message */ 44 if (msg[0] != 0x00 || msg[1] != 0x01) 45 return NULL; 46 47 for (i = 2; i < modulus_len - 1; i++) 48 if (msg[i] != 0xFF) 49 break; 50 51 /* separator check */ 52 if (msg[i] != 0) 53 /* There was no octet with hexadecimal value 0x00 54 to separate ps from m. */ 55 return NULL; 56 57 ps_len = i - 2; 58 59 *outlen = (msglen - (2 + ps_len + 1)); 60 61 return msg + 2 + ps_len + 1; 62 } 63 64 /* 65 * RSA Signature verification with public key 66 */ 67 static int digsig_verify_rsa(struct key *key, 68 const char *sig, int siglen, 69 const char *h, int hlen) 70 { 71 int err = -EINVAL; 72 unsigned long len; 73 unsigned long mlen, mblen; 74 unsigned int l; 75 int head, i; 76 unsigned char *out1 = NULL; 77 const char *m; 78 MPI pkey[2]; 79 uint8_t *p, *datap; 80 const uint8_t *endp; 81 const struct user_key_payload *ukp; 82 struct pubkey_hdr *pkh; 83 84 down_read(&key->sem); 85 ukp = user_key_payload_locked(key); 86 87 if (!ukp) { 88 /* key was revoked before we acquired its semaphore */ 89 err = -EKEYREVOKED; 90 goto err1; 91 } 92 93 if (ukp->datalen < sizeof(*pkh)) 94 goto err1; 95 96 pkh = (struct pubkey_hdr *)ukp->data; 97 98 if (pkh->version != 1) 99 goto err1; 100 101 if (pkh->algo != PUBKEY_ALGO_RSA) 102 goto err1; 103 104 if (pkh->nmpi != 2) 105 goto err1; 106 107 datap = pkh->mpi; 108 endp = ukp->data + ukp->datalen; 109 110 for (i = 0; i < pkh->nmpi; i++) { 111 unsigned int remaining = endp - datap; 112 pkey[i] = mpi_read_from_buffer(datap, &remaining); 113 if (IS_ERR(pkey[i])) { 114 err = PTR_ERR(pkey[i]); 115 goto free_keys; 116 } 117 datap += remaining; 118 } 119 120 mblen = mpi_get_nbits(pkey[0]); 121 mlen = DIV_ROUND_UP(mblen, 8); 122 123 if (mlen == 0) { 124 err = -EINVAL; 125 goto free_keys; 126 } 127 128 err = -ENOMEM; 129 130 out1 = kzalloc(mlen, GFP_KERNEL); 131 if (!out1) 132 goto free_keys; 133 134 { 135 unsigned int nret = siglen; 136 MPI in __free(mpi_free) = mpi_read_from_buffer(sig, &nret); 137 138 if (IS_ERR(in)) { 139 err = PTR_ERR(in); 140 goto in_exit; 141 } 142 143 { 144 MPI res __free(mpi_free) = mpi_alloc(mpi_get_nlimbs(in) * 2); 145 146 if (!res) 147 goto res_exit; 148 149 err = mpi_powm(res, in, pkey[1], pkey[0]); 150 if (err) 151 goto res_exit; 152 153 if (mpi_get_nlimbs(res) * BYTES_PER_MPI_LIMB > mlen) { 154 err = -EINVAL; 155 goto res_exit; 156 } 157 158 p = mpi_get_buffer(res, &l, NULL); 159 if (!p) { 160 err = -EINVAL; 161 goto res_exit; 162 } 163 164 len = mlen; 165 head = len - l; 166 memset(out1, 0, head); 167 memcpy(out1 + head, p, l); 168 169 kfree(p); 170 171 m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len); 172 173 if (!m || len != hlen || memcmp(m, h, hlen)) 174 err = -EINVAL; 175 res_exit: > 176 } 177 in_exit: 178 } 179 180 kfree(out1); 181 free_keys: 182 while (--i >= 0) 183 mpi_free(pkey[i]); 184 err1: 185 up_read(&key->sem); 186 187 return err; 188 } 189 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki