When "cp >= barg_buf + BARG_LEN-2", it breaks internel looping 'while', but outside loop 'for' still has effect, so "*cp++ = ' '" will continue repeating which may cause memory overflow. So need additional length check for it in the outside looping. Also beautify the related code which found by "./scripts/checkpatch.pl" Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			62 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			62 lines
		
	
	
	
		
			1.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * bootstr.c:  Boot string/argument acquisition from the PROM.
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 *
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 * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu)
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 */
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#include <linux/string.h>
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#include <asm/oplib.h>
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#include <linux/init.h>
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#define BARG_LEN  256
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static char barg_buf[BARG_LEN] = { 0 };
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static char fetched __initdata = 0;
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char * __init
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prom_getbootargs(void)
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{
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	int iter;
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	char *cp, *arg;
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	/* This check saves us from a panic when bootfd patches args. */
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	if (fetched) {
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		return barg_buf;
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	}
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	switch (prom_vers) {
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	case PROM_V0:
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		cp = barg_buf;
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		/* Start from 1 and go over fd(0,0,0)kernel */
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		for (iter = 1; iter < 8; iter++) {
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			arg = (*(romvec->pv_v0bootargs))->argv[iter];
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			if (arg == NULL)
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				break;
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			while (*arg != 0) {
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				/* Leave place for space and null. */
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				if (cp >= barg_buf + BARG_LEN - 2)
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					/* We might issue a warning here. */
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					break;
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				*cp++ = *arg++;
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			}
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			*cp++ = ' ';
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			if (cp >= barg_buf + BARG_LEN - 1)
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				/* We might issue a warning here. */
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				break;
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		}
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		*cp = 0;
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		break;
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	case PROM_V2:
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	case PROM_V3:
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		/*
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		 * V3 PROM cannot supply as with more than 128 bytes
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		 * of an argument. But a smart bootstrap loader can.
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		 */
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		strlcpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf));
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		break;
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	default:
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		break;
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	}
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	fetched = 1;
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	return barg_buf;
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}
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