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Revision b3118bdc91876cbc04b7e81dcf7bea71d86ce4f8 authored by Shawn O. Pearce on 14 October 2009, 14:23:51 UTC, committed by Junio C Hamano on 14 October 2009, 20:39:37 UTC 
sha1_file: Fix infinite loop when pack is corrupted
 
Some types of corruption to a pack may confuse the deflate stream
which stores an object.  In Andy's reported case a 36 byte region
of the pack was overwritten, leading to what appeared to be a valid
deflate stream that was trying to produce a result larger than our
allocated output buffer could accept.

Z_BUF_ERROR is returned from inflate() if either the input buffer
needs more input bytes, or the output buffer has run out of space.
Previously we only considered the former case, as it meant we needed
to move the stream's input buffer to the next window in the pack.

We now abort the loop if inflate() returns Z_BUF_ERROR without
consuming the entire input buffer it was given, or has filled
the entire output buffer but has not yet returned Z_STREAM_END.
Either state is a clear indicator that this loop is not working
as expected, and should not continue.

This problem cannot occur with loose objects as we open the entire
loose object as a single buffer and treat Z_BUF_ERROR as an error.

Reported-by: Andy Isaacson <adi@hexapodia.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 583371a
Raw File
var.c 
/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Eric Biederman, 2005
 */
#include "cache.h"
#include "exec_cmd.h"

static const char var_usage[] = "git var [-l | <variable>]";

struct git_var {
	const char *name;
	const char *(*read)(int);
};
static struct git_var git_vars[] = {
	{ "GIT_COMMITTER_IDENT", git_committer_info },
	{ "GIT_AUTHOR_IDENT",   git_author_info },
	{ "", NULL },
};

static void list_vars(void)
{
	struct git_var *ptr;
	for (ptr = git_vars; ptr->read; ptr++)
		printf("%s=%s\n", ptr->name, ptr->read(IDENT_WARN_ON_NO_NAME));
}

static const char *read_var(const char *var)
{
	struct git_var *ptr;
	const char *val;
	val = NULL;
	for (ptr = git_vars; ptr->read; ptr++) {
		if (strcmp(var, ptr->name) == 0) {
			val = ptr->read(IDENT_ERROR_ON_NO_NAME);
			break;
		}
	}
	return val;
}

static int show_config(const char *var, const char *value, void *cb)
{
	if (value)
		printf("%s=%s\n", var, value);
	else
		printf("%s\n", var);
	return git_default_config(var, value, cb);
}

int main(int argc, char **argv)
{
	const char *val;
	int nongit;
	if (argc != 2) {
		usage(var_usage);
	}

	git_extract_argv0_path(argv[0]);

	setup_git_directory_gently(&nongit);
	val = NULL;

	if (strcmp(argv[1], "-l") == 0) {
		git_config(show_config, NULL);
		list_vars();
		return 0;
	}
	git_config(git_default_config, NULL);
	val = read_var(argv[1]);
	if (!val)
		usage(var_usage);

	printf("%s\n", val);

	return 0;
}
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