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v0.8.1
Revision 64cc1c0909949fa2866ad71ad2d1ab7ccaa673d9 authored by Martin Koegler on 06 January 2008, 17:21:10 UTC, committed by Junio C Hamano on 07 January 2008, 02:41:44 UTC 
tree-walk: don't parse incorrect entries
 
The current code can access memory outside of the tree buffer in the
case of malformed tree entries.

This patch prevents this by:

 * The rest of the buffer must be at least 24 bytes (at least 1 byte
   mode, 1 blank, at least one byte path name, 1 NUL, 20 bytes sha1).

 * Check that the last NUL (21 bytes before the end) is present.
   This ensures that strlen() and get_mode() calls stay within the
   buffer.

 * The mode may not be empty. We have only to reject a blank at the
   begin, as the rest is handled by if (c < '0' || c > '7').

 * The blank is ensured by get_mode().

 * The path must contain at least one character.

Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 47ee06f
Raw File
builtin-merge-base.c 
#include "builtin.h"
#include "cache.h"
#include "commit.h"

static int show_merge_base(struct commit *rev1, struct commit *rev2, int show_all)
{
	struct commit_list *result = get_merge_bases(rev1, rev2, 0);

	if (!result)
		return 1;

	while (result) {
		printf("%s\n", sha1_to_hex(result->item->object.sha1));
		if (!show_all)
			return 0;
		result = result->next;
	}

	return 0;
}

static const char merge_base_usage[] =
"git-merge-base [--all] <commit-id> <commit-id>";

int cmd_merge_base(int argc, const char **argv, const char *prefix)
{
	struct commit *rev1, *rev2;
	unsigned char rev1key[20], rev2key[20];
	int show_all = 0;

	git_config(git_default_config);

	while (1 < argc && argv[1][0] == '-') {
		const char *arg = argv[1];
		if (!strcmp(arg, "-a") || !strcmp(arg, "--all"))
			show_all = 1;
		else
			usage(merge_base_usage);
		argc--; argv++;
	}
	if (argc != 3)
		usage(merge_base_usage);
	if (get_sha1(argv[1], rev1key))
		die("Not a valid object name %s", argv[1]);
	if (get_sha1(argv[2], rev2key))
		die("Not a valid object name %s", argv[2]);
	rev1 = lookup_commit_reference(rev1key);
	rev2 = lookup_commit_reference(rev2key);
	if (!rev1 || !rev2)
		return 1;
	return show_merge_base(rev1, rev2, show_all);
}
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