From b5d9ba8fe64a0aacf99fd1eec10375a98104a5ea Mon Sep 17 00:00:00 2001 From: Avi Fishman Date: Thu, 5 Oct 2017 11:25:16 +0200 Subject: [PATCH] i2cset: fix 'i' & 's' modes (3 extra bytes were sent) When 'i' or 's' modes are selected block array is filled from offset 3 (blen = 3) but copied to data.block buffer from offset 0 so first 3 bytes contains garbage from stack. The buffer that is sent is also 3 bytes too long due to those extra 3 bytes. Signed-off-by: Avi Fishman Signed-off-by: Denys Vlasenko --- miscutils/i2c_tools.c | 40 +++++++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 13 deletions(-) diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c index fc392d9dc..82f9842bd 100644 --- a/miscutils/i2c_tools.c +++ b/miscutils/i2c_tools.c @@ -562,14 +562,19 @@ int i2cset_main(int argc, char **argv) opt_m = (1 << 2), opt_r = (1 << 3); int bus_num, bus_addr, data_addr, mode = I2C_SMBUS_BYTE, pec = 0; - int val, blen = 0, mask = 0, fd, status; + int val, blen, mask, fd, status; unsigned char block[I2C_SMBUS_BLOCK_MAX]; char *opt_m_arg = NULL; unsigned opts; - opts = getopt32(argv, "^" "fym:r" "\0" "-3"/*from 3 to ? args*/, &opt_m_arg); + opts = getopt32(argv, "^" + "fym:r" + "\0" "-3", /* minimum 3 args */ + &opt_m_arg + ); argv += optind; argc -= optind; + argc--; /* now argv[argc] is last arg */ bus_num = i2c_bus_lookup(argv[0]); bus_addr = i2c_parse_bus_addr(argv[1]); @@ -579,20 +584,26 @@ int i2cset_main(int argc, char **argv) if (!argv[4] && argv[3][0] != 'c') { mode = I2C_SMBUS_BYTE_DATA; /* Implicit b */ } else { - switch (argv[argc-1][0]) { - case 'c': /* Already set */ break; - case 'b': mode = I2C_SMBUS_BYTE_DATA; break; - case 'w': mode = I2C_SMBUS_WORD_DATA; break; - case 's': mode = I2C_SMBUS_BLOCK_DATA; break; - case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA; break; + switch (argv[argc][0]) { + case 'c': /* Already set */ + break; + case 'b': mode = I2C_SMBUS_BYTE_DATA; + break; + case 'w': mode = I2C_SMBUS_WORD_DATA; + break; + case 's': mode = I2C_SMBUS_BLOCK_DATA; + break; + case 'i': mode = I2C_SMBUS_I2C_BLOCK_DATA; + break; default: bb_error_msg("invalid mode"); bb_show_usage(); } - pec = argv[argc-1][1] == 'p'; - if (mode == I2C_SMBUS_BLOCK_DATA || - mode == I2C_SMBUS_I2C_BLOCK_DATA) { + pec = (argv[argc][1] == 'p'); + if (mode == I2C_SMBUS_BLOCK_DATA + || mode == I2C_SMBUS_I2C_BLOCK_DATA + ) { if (pec && mode == I2C_SMBUS_I2C_BLOCK_DATA) bb_error_msg_and_die( "PEC not supported for I2C " @@ -606,6 +617,8 @@ int i2cset_main(int argc, char **argv) } /* Prepare the value(s) to be written according to current mode. */ + mask = 0; + blen = 0; switch (mode) { case I2C_SMBUS_BYTE_DATA: val = xstrtou_range(argv[3], 0, 0, 0xff); @@ -615,8 +628,9 @@ int i2cset_main(int argc, char **argv) break; case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_I2C_BLOCK_DATA: - for (blen = 3; blen < (argc - 1); blen++) - block[blen] = xstrtou_range(argv[blen], 0, 0, 0xff); + for (blen = 3; blen < argc; blen++) + block[blen - 3] = xstrtou_range(argv[blen], 0, 0, 0xff); + blen -= 3; val = -1; break; default: -- 2.25.1