Revision 3ec804490a265f4c418a321428c12f3f18b7eff5 authored by Jeff King on 29 April 2017, 12:36:44 UTC, committed by Junio C Hamano on 05 May 2017, 03:07:27 UTC
When a remote server uses git-shell, the client side will
connect to it like:

  ssh server "git-upload-pack 'foo.git'"

and we literally exec ("git-upload-pack", "foo.git"). In
early versions of upload-pack and receive-pack, we took a
repository argument and nothing else. But over time they
learned to accept dashed options. If the user passes a
repository name that starts with a dash, the results are
confusing at best (we complain of a bogus option instead of
a non-existent repository) and malicious at worst (the user
can start an interactive pager via "--help").

We could pass "--" to the sub-process to make sure the
user's argument is interpreted as a branch name. I.e.:

  git-upload-pack -- -foo.git

But adding "--" automatically would make us inconsistent
with a normal shell (i.e., when git-shell is not in use),
where "-foo.git" would still be an error. For that case, the
client would have to specify the "--", but they can't do so
reliably, as existing versions of git-shell do not allow
more than a single argument.

The simplest thing is to simply disallow "-" at the start of
the repo name argument. This hasn't worked either with or
without git-shell since version 1.0.0, and nobody has
complained.

Note that this patch just applies to do_generic_cmd(), which
runs upload-pack, receive-pack, and upload-archive. There
are two other types of commands that git-shell runs:

  - do_cvs_cmd(), but this already restricts the argument to
    be the literal string "server"

  - admin-provided commands in the git-shell-commands
    directory. We'll pass along arbitrary arguments there,
    so these commands could have similar problems. But these
    commands might actually understand dashed arguments, so
    we cannot just block them here. It's up to the writer of
    the commands to make sure they are safe. With great
    power comes great responsibility.

Reported-by: Timo Schmid <tschmid@ernw.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 7654286
Raw File
utf8.h
#ifndef GIT_UTF8_H
#define GIT_UTF8_H

typedef unsigned int ucs_char_t;  /* assuming 32bit int */

size_t display_mode_esc_sequence_len(const char *s);
int utf8_width(const char **start, size_t *remainder_p);
int utf8_strnwidth(const char *string, int len, int skip_ansi);
int utf8_strwidth(const char *string);
int is_utf8(const char *text);
int is_encoding_utf8(const char *name);
int same_encoding(const char *, const char *);
__attribute__((format (printf, 2, 3)))
int utf8_fprintf(FILE *, const char *, ...);

extern const char utf8_bom[];
extern int skip_utf8_bom(char **, size_t);

void strbuf_add_wrapped_text(struct strbuf *buf,
		const char *text, int indent, int indent2, int width);
void strbuf_add_wrapped_bytes(struct strbuf *buf, const char *data, int len,
			     int indent, int indent2, int width);
void strbuf_utf8_replace(struct strbuf *sb, int pos, int width,
			 const char *subst);

#ifndef NO_ICONV
char *reencode_string_iconv(const char *in, size_t insz,
			    iconv_t conv, int *outsz);
char *reencode_string_len(const char *in, int insz,
			  const char *out_encoding,
			  const char *in_encoding,
			  int *outsz);
#else
static inline char *reencode_string_len(const char *a, int b,
					const char *c, const char *d, int *e)
{ if (e) *e = 0; return NULL; }
#endif

static inline char *reencode_string(const char *in,
				    const char *out_encoding,
				    const char *in_encoding)
{
	return reencode_string_len(in, strlen(in),
				   out_encoding, in_encoding,
				   NULL);
}

int mbs_chrlen(const char **text, size_t *remainder_p, const char *encoding);

/*
 * Returns true if the the path would match ".git" after HFS case-folding.
 * The path should be NUL-terminated, but we will match variants of both ".git\0"
 * and ".git/..." (but _not_ ".../.git"). This makes it suitable for both fsck
 * and verify_path().
 */
int is_hfs_dotgit(const char *path);

#endif
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