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  1. 26 9月, 2015 20 次提交
    • J
      compat/hstrerror: convert sprintf to snprintf · 48bdf869
      由 Jeff King 提交于 
      This is a trivially correct use of sprintf, as our error
number should not be excessively long. But it's still nice
to drop an sprintf call.

Note that we cannot use xsnprintf here, because this is
compat code which does not load git-compat-util.h.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      48bdf869
    • J
      stop_progress_msg: convert sprintf to xsnprintf · f5691aa6
      由 Jeff King 提交于 
      The usual arguments for using xsnprintf over sprintf apply,
but this case is a little tricky. We print to a fixed-size
buffer if we have room, and otherwise to an allocated
buffer. So there should be no overflow here, but it is still
good to communicate our intention, as well as to check our
earlier math for how much space the string will need.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      f5691aa6
    • J
      find_short_object_filename: convert sprintf to xsnprintf · c3bb0ac7
      由 Jeff King 提交于 
      We use sprintf() to format some hex data into a buffer. The
buffer is clearly long enough, and using snprintf here is
not necessary. And in fact, it does not really make anything
easier to audit, as the size we feed to snprintf accounts
for the magic extra 42 bytes found in each alt->name field
of struct alternate_object_database (which is there exactly
to do this formatting).

Still, it is nice to remove an sprintf call and replace it
with an xsnprintf and explanatory comment, which makes it
easier to audit the code base for overflows.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      c3bb0ac7
    • J
      use xsnprintf for generating git object headers · ef1286d3
      由 Jeff King 提交于 
      We generally use 32-byte buffers to format git's "type size"
header fields. These should not generally overflow unless
you can produce some truly gigantic objects (and our types
come from our internal array of constant strings). But it is
a good idea to use xsnprintf to make sure this is the case.

Note that we slightly modify the interface to
write_sha1_file_prepare, which nows uses "hdrlen" as an "in"
parameter as well as an "out" (on the way in it stores the
allocated size of the header, and on the way out it returns
the ultimate size of the header).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      ef1286d3
    • J
      archive-tar: use xsnprintf for trivial formatting · f2f02675
      由 Jeff King 提交于 
      When we generate tar headers, we sprintf() values directly
into a struct with the fixed-size header values. For the
most part this is fine, as we are formatting small values
(e.g., the octal format of "mode & 0x7777" is of fixed
length). But it's still a good idea to use xsnprintf here.
It communicates to readers what our expectation is, and it
provides a run-time check that we are not overflowing the
buffers.

The one exception here is the mtime, which comes from the
epoch time of the commit we are archiving. For sane values,
this fits into the 12-byte value allocated in the header.
But since git can handle 64-bit times, if I claim to be a
visitor from the year 10,000 AD, I can overflow the buffer.
This turns out to be harmless, as we simply overflow into
the chksum field, which is then overwritten.

This case is also best as an xsnprintf. It should never come
up, short of extremely malformed dates, and in that case we
are probably better off dying than silently truncating the
date value (and we cannot expand the size of the buffer,
since it is dictated by the ustar format). Our friends in
the year 5138 (when we legitimately flip to a 12-digit
epoch) can deal with that problem then.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      f2f02675
    • J
      convert trivial sprintf / strcpy calls to xsnprintf · 5096d490
      由 Jeff King 提交于 
      We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.

However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      5096d490
    • J
      compat/inet_ntop: fix off-by-one in inet_ntop4 · db85a8a9
      由 Jeff King 提交于 
      Our compat inet_ntop4 function writes to a temporary buffer
with snprintf, and then uses strcpy to put the result into
the final "dst" buffer. We check the return value of
snprintf against the size of "dst", but fail to account for
the NUL terminator. As a result, we may overflow "dst" with
a single NUL. In practice, this doesn't happen because the
output of inet_ntop is limited, and we provide buffers that
are way oversized.

We can fix the off-by-one check easily, but while we are
here let's also use strlcpy for increased safety, just in
case there are other bugs lurking.

As a side note, this compat code seems to be BSD-derived.
Searching for "vixie inet_ntop" turns up NetBSD's latest
version of the same code, which has an identical fix (and
switches to strlcpy, too!).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      db85a8a9
    • J
      test-dump-cache-tree: avoid overflow of cache-tree name · 04724222
      由 Jeff King 提交于 
      When dumping a cache-tree, we sprintf sub-tree names directly
into a fixed-size buffer, which can overflow. We can
trivially fix this by converting to xsnprintf to at least
notice and die.

This probably should handle arbitrary-sized names, but
there's not much point. It's used only by the test scripts,
so the trivial fix is enough.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      04724222
    • J
      progress: store throughput display in a strbuf · 3131977d
      由 Jeff King 提交于 
      Coverity noticed that we strncpy() into a fixed-size buffer
without making sure that it actually ended up
NUL-terminated. This is unlikely to be a bug in practice,
since throughput strings rarely hit 32 characters, but it
would be nice to clean it up.

The most obvious way to do so is to add a NUL-terminator.
But instead, this patch switches the fixed-size buffer out
for a strbuf. At first glance this seems much less
efficient, until we realize that filling in the fixed-size
buffer is done by writing into a strbuf and copying the
result!

By writing straight to the buffer, we actually end up more
efficient:

  1. We avoid an extra copy of the bytes.

  2. Rather than malloc/free each time progress is shown, we
     can strbuf_reset and use the same buffer each time.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      3131977d
    • J
      trace: use strbuf for quote_crnl output · 0bb443fd
      由 Jeff King 提交于 
      When we output GIT_TRACE_SETUP paths, we quote any
meta-characters. But our buffer to hold the result is only
PATH_MAX bytes, and we could double the size of the input
path (if every character needs quoting). We could use a
2*PATH_MAX buffer, if we assume the input will never be more
than PATH_MAX. But it's easier still to just switch to a
strbuf and not worry about whether the input can exceed
PATH_MAX or not.

The original copied the "p2" pointer to "p1", advancing
both. Since this gets rid of "p1", let's also drop "p2",
whose name is now confusing. We can just advance the
original "path" pointer.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      0bb443fd
    • J
      mailsplit: make PATH_MAX buffers dynamic · 1d895f19
      由 Jeff King 提交于 
      There are several PATH_MAX-sized buffers in mailsplit, along
with some questionable uses of sprintf.  These are not
really of security interest, as local mailsplit pathnames
are not typically under control of an attacker, and you
could generally only overflow a few numbers at the end of a
path that approaches PATH_MAX (a longer path would choke
mailsplit long before). But it does not hurt to be careful,
and as a bonus we lift some limits for systems with
too-small PATH_MAX varibles.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      1d895f19
    • J
      fsck: use strbuf to generate alternate directories · c1fd0809
      由 Jeff King 提交于 
      When fsck-ing alternates, we make a copy of the alternate
directory in a fixed PATH_MAX buffer. We memcpy directly,
without any check whether we are overflowing the buffer.
This is OK if PATH_MAX is a true representation of the
maximum path on the system, because any path here will have
already been vetted by the alternates subsystem. But that is
not true on every system, so we should be more careful.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      c1fd0809
    • J
      add reentrant variants of sha1_to_hex and find_unique_abbrev · af49c6d0
      由 Jeff King 提交于 
      The sha1_to_hex and find_unique_abbrev functions always
write into reusable static buffers. There are a few problems
with this:

  - future calls overwrite our result. This is especially
    annoying with find_unique_abbrev, which does not have a
    ring of buffers, so you cannot even printf() a result
    that has two abbreviated sha1s.

  - if you want to put the result into another buffer, we
    often strcpy, which looks suspicious when auditing for
    overflows.

This patch introduces sha1_to_hex_r and find_unique_abbrev_r,
which write into a user-provided buffer. Of course this is
just punting on the overflow-auditing, as the buffer
obviously needs to be GIT_SHA1_HEXSZ + 1 bytes. But it is
much easier to audit, since that is a well-known size.

We retain the non-reentrant forms, which just become thin
wrappers around the reentrant ones. This patch also adds a
strbuf variant of find_unique_abbrev, which will be handy in
later patches.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      af49c6d0
    • J
      strbuf: make strbuf_complete_line more generic · 399ad553
      由 Jeff King 提交于 
      The strbuf_complete_line function makes sure that a buffer
ends in a newline. But we may want to do this for any
character (e.g., "/" on the end of a path). Let's factor out
a generic version, and keep strbuf_complete_line as a thin
wrapper.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      399ad553
    • J
      add git_path_buf helper function · bb3788ce
      由 Jeff King 提交于 
      If you have a function that uses git_path a lot, but would
prefer to avoid the static buffers, it's useful to keep a
single scratch buffer locally and reuse it for each call.
You used to be able to do this with git_snpath:

  char buf[PATH_MAX];

  foo(git_snpath(buf, sizeof(buf), "foo"));
  bar(git_snpath(buf, sizeof(buf), "bar"));

but since 1a83c240, git_snpath has been replaced with
strbuf_git_path. This is good, because it removes the
arbitrary PATH_MAX limit. But using strbuf_git_path is more
awkward for two reasons:

  1. It adds to the buffer, rather than replacing it. This
     is consistent with other strbuf functions, but makes
     reuse of a single buffer more tedious.

  2. It doesn't return the buffer, so you can't format
     as part of a function's arguments.

The new git_path_buf solves both of these, so you can use it
like:

  struct strbuf buf = STRBUF_INIT;

  foo(git_path_buf(&buf, "foo"));
  bar(git_path_buf(&buf, "bar"));

  strbuf_release(&buf);
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      bb3788ce
    • J
      add xsnprintf helper function · 7b03c89e
      由 Jeff King 提交于 
      There are a number of places in the code where we call
sprintf(), with the assumption that the output will fit into
the buffer. In many cases this is true (e.g., formatting a
number into a large buffer), but it is hard to tell
immediately from looking at the code. It would be nice if we
had some run-time check to make sure that our assumption is
correct (and to communicate to readers of the code that we
are not blindly calling sprintf, but have actually thought
about this case).

This patch introduces xsnprintf, which behaves just like
snprintf, except that it dies whenever the output is
truncated. This acts as a sort of assert() for these cases,
which can help find places where the assumption is violated
(as opposed to truncating and proceeding, which may just
silently give a wrong answer).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      7b03c89e
    • J
      fsck: don't fsck alternates for connectivity-only check · fbe85e73
      由 Jeff King 提交于 
      Commit 02976bf8 (fsck: introduce `git fsck --connectivity-only`,
2015-06-22) recently gave fsck an option to perform only a
subset of the checks, by skipping the fsck_object_dir()
call. However, it does so only for the local object
directory, and we still do expensive checks on any alternate
repos. We should skip them in this case, too.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      fbe85e73
    • J
      archive-tar: fix minor indentation violation · 108332c7
      由 Jeff King 提交于 
      This looks like a simple omission from 85390709 (archive-tar:
unindent write_tar_entry by one level, 2012-05-03).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      108332c7
    • J
      mailsplit: fix FILE* leak in split_maildir · d270d7b7
      由 Jeff King 提交于 
      If we encounter an error while splitting a maildir, we exit
the function early, leaking the open filehandle. This isn't
a big deal, since we exit the program soon after, but it's
easy enough to be careful.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      d270d7b7
    • J
      show-branch: avoid segfault with --reflog of unborn branch · 7cd17e80
      由 Jeff King 提交于 
      When no branch is given to the "--reflog" option, we resolve
HEAD to get the default branch. However, if HEAD points to
an unborn branch, resolve_ref returns NULL, and we later
segfault trying to access it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
      7cd17e80
  3. 22 9月, 2015 5 次提交
  5. 21 9月, 2015 10 次提交
  7. 18 9月, 2015 5 次提交