drivers/crypto/aspeed/aspeed-acry.c:295 aspeed_acry_rsa_ctx_copy() error: uninitialized symbol 'idx'.

drivers/crypto/aspeed/aspeed-acry.c:295 aspeed_acry_rsa_ctx_copy() error: uninitialized symbol 'idx'.

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   1ec35eadc3b448c91a6b763371a7073444e95f9d
commit: 2f1cf4e50c956f882c9fc209c7cded832b67b8a3 crypto: aspeed - Add ACRY RSA driver
config: m68k-randconfig-m031-20230226 (https://download.01.org/0day-ci/archive/20230226/202302261052.CVFRyq6F-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Link: https://lore.kernel.org/r/202302261052.CVFRyq6F-lkp@intel.com/

smatch warnings:
drivers/crypto/aspeed/aspeed-acry.c:295 aspeed_acry_rsa_ctx_copy() error: uninitialized symbol 'idx'.

vim +/idx +295 drivers/crypto/aspeed/aspeed-acry.c

2f1cf4e50c956f Neal Liu 2023-01-04  250  static int aspeed_acry_rsa_ctx_copy(struct aspeed_acry_dev *acry_dev, void *buf,
2f1cf4e50c956f Neal Liu 2023-01-04  251  				    const void *xbuf, size_t nbytes,
2f1cf4e50c956f Neal Liu 2023-01-04  252  				    enum aspeed_rsa_key_mode mode)
2f1cf4e50c956f Neal Liu 2023-01-04  253  {
2f1cf4e50c956f Neal Liu 2023-01-04  254  	const u8 *src = xbuf;
2f1cf4e50c956f Neal Liu 2023-01-04  255  	u32 *dw_buf = (u32 *)buf;
2f1cf4e50c956f Neal Liu 2023-01-04  256  	int nbits, ndw;
2f1cf4e50c956f Neal Liu 2023-01-04  257  	int i, j, idx;
2f1cf4e50c956f Neal Liu 2023-01-04  258  	u32 data = 0;
2f1cf4e50c956f Neal Liu 2023-01-04  259  
2f1cf4e50c956f Neal Liu 2023-01-04  260  	ACRY_DBG(acry_dev, "nbytes:%zu, mode:%d\n", nbytes, mode);
2f1cf4e50c956f Neal Liu 2023-01-04  261  
2f1cf4e50c956f Neal Liu 2023-01-04  262  	if (nbytes > ASPEED_ACRY_RSA_MAX_KEY_LEN)
2f1cf4e50c956f Neal Liu 2023-01-04  263  		return -ENOMEM;
2f1cf4e50c956f Neal Liu 2023-01-04  264  
2f1cf4e50c956f Neal Liu 2023-01-04  265  	/* Remove the leading zeros */
2f1cf4e50c956f Neal Liu 2023-01-04  266  	while (nbytes > 0 && src[0] == 0) {
2f1cf4e50c956f Neal Liu 2023-01-04  267  		src++;
2f1cf4e50c956f Neal Liu 2023-01-04  268  		nbytes--;
2f1cf4e50c956f Neal Liu 2023-01-04  269  	}
2f1cf4e50c956f Neal Liu 2023-01-04  270  
2f1cf4e50c956f Neal Liu 2023-01-04  271  	nbits = nbytes * 8;
2f1cf4e50c956f Neal Liu 2023-01-04  272  	if (nbytes > 0)
2f1cf4e50c956f Neal Liu 2023-01-04  273  		nbits -= count_leading_zeros(src[0]) - (BITS_PER_LONG - 8);
2f1cf4e50c956f Neal Liu 2023-01-04  274  
2f1cf4e50c956f Neal Liu 2023-01-04  275  	/* double-world alignment */
2f1cf4e50c956f Neal Liu 2023-01-04  276  	ndw = DIV_ROUND_UP(nbytes, BYTES_PER_DWORD);
2f1cf4e50c956f Neal Liu 2023-01-04  277  
2f1cf4e50c956f Neal Liu 2023-01-04  278  	if (nbytes > 0) {
2f1cf4e50c956f Neal Liu 2023-01-04  279  		i = BYTES_PER_DWORD - nbytes % BYTES_PER_DWORD;
2f1cf4e50c956f Neal Liu 2023-01-04  280  		i %= BYTES_PER_DWORD;
2f1cf4e50c956f Neal Liu 2023-01-04  281  
2f1cf4e50c956f Neal Liu 2023-01-04  282  		for (j = ndw; j > 0; j--) {
2f1cf4e50c956f Neal Liu 2023-01-04  283  			for (; i < BYTES_PER_DWORD; i++) {
2f1cf4e50c956f Neal Liu 2023-01-04  284  				data <<= 8;
2f1cf4e50c956f Neal Liu 2023-01-04  285  				data |= *src++;
2f1cf4e50c956f Neal Liu 2023-01-04  286  			}
2f1cf4e50c956f Neal Liu 2023-01-04  287  
2f1cf4e50c956f Neal Liu 2023-01-04  288  			i = 0;
2f1cf4e50c956f Neal Liu 2023-01-04  289  
2f1cf4e50c956f Neal Liu 2023-01-04  290  			if (mode == ASPEED_RSA_EXP_MODE)
2f1cf4e50c956f Neal Liu 2023-01-04  291  				idx = acry_dev->exp_dw_mapping[j - 1];
2f1cf4e50c956f Neal Liu 2023-01-04  292  			else if (mode == ASPEED_RSA_MOD_MODE)
2f1cf4e50c956f Neal Liu 2023-01-04  293  				idx = acry_dev->mod_dw_mapping[j - 1];

idx not initialized for if it's not EXPR and not MOD.  Just do:
	} else { /* mode == ASPEED_RSA_MOD_MODE */
		idx = acry_dev->mod_dw_mapping[j - 1];
	}

2f1cf4e50c956f Neal Liu 2023-01-04  294  
2f1cf4e50c956f Neal Liu 2023-01-04 @295  			dw_buf[idx] = cpu_to_le32(data);
2f1cf4e50c956f Neal Liu 2023-01-04  296  		}
2f1cf4e50c956f Neal Liu 2023-01-04  297  	}
2f1cf4e50c956f Neal Liu 2023-01-04  298  
2f1cf4e50c956f Neal Liu 2023-01-04  299  	return nbits;
2f1cf4e50c956f Neal Liu 2023-01-04  300  }

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