967e82cae0
System V compatibility option (malloc "V" flag) is in effect a zero sized reallocf() could cause a double free. PR: bin/141753 Submitted by: Dan Lukes
49 lines
1.8 KiB
C
49 lines
1.8 KiB
C
/*-
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* Copyright (c) 1998, M. Warner Losh <imp@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <stdlib.h>
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void *
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reallocf(void *ptr, size_t size)
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{
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void *nptr;
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nptr = realloc(ptr, size);
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/*
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* When the System V compatibility option (malloc "V" flag) is
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* in effect, realloc(ptr, 0) frees the memory and returns NULL.
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* So, to avoid double free, call free() only when size != 0.
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* realloc(ptr, 0) can't fail when ptr != NULL.
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*/
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if (!nptr && ptr && size != 0)
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free(ptr);
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return (nptr);
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}
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