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21780f89d6
The strlen() may go too far when estimating the length of the given string. In some cases it may go over the boundary and crash the system which is the case according to the commit 13a55372b64e ("ARM: orion5x: Revert commit 4904dbda41c8."). Rectify this by switching to strnlen() for the expected maximum length of the string. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108141108.62974-1-andriy.shevchenko@linux.intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
29 lines
674 B
C
29 lines
674 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/string.h>
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#include <linux/if_ether.h>
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#include <linux/ctype.h>
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#include <linux/kernel.h>
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bool mac_pton(const char *s, u8 *mac)
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{
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size_t maxlen = 3 * ETH_ALEN - 1;
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int i;
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/* XX:XX:XX:XX:XX:XX */
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if (strnlen(s, maxlen) < maxlen)
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return false;
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/* Don't dirty result unless string is valid MAC. */
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for (i = 0; i < ETH_ALEN; i++) {
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if (!isxdigit(s[i * 3]) || !isxdigit(s[i * 3 + 1]))
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return false;
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if (i != ETH_ALEN - 1 && s[i * 3 + 2] != ':')
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return false;
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}
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for (i = 0; i < ETH_ALEN; i++) {
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mac[i] = (hex_to_bin(s[i * 3]) << 4) | hex_to_bin(s[i * 3 + 1]);
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}
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return true;
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}
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EXPORT_SYMBOL(mac_pton);
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