Commit Graph

39 Commits

Author SHA1 Message Date
Jason A. Donenfeld
bdae1d8a8d White space around control verbs.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2013-03-04 09:12:54 -05:00
Jim Meyering
61d4147ea2 do not write outside heap buffer
* parsing.c (substr): Handle tail < head.

This started when I noticed some cgit segfaults on savannah.gnu.org.
Finding the offending URL/commit and then constructing a stand-alone
reproducer were far more time-consuming than writing the actual patch.

The problem arises with a commit like this, in which the user name
part of the "Author" field is empty:

    $ git log -1
    commit 6f3f41d73393278f3ede68a2cb1e7a2a23fa3421
    Author: <T at h.or>
    Date:   Mon Apr 23 22:29:16 2012 +0200

Here's what happens:

(this is due to buf=malloc(0); strncpy (buf, head, -1);
 where "head" may point to plenty of attacker-specified non-NUL bytes,
 so we can overwrite a zero-length heap buffer with arbitrary data)

 Invalid write of size 1
    at 0x4A09361: strncpy (mc_replace_strmem.c:463)
    by 0x408977: substr (parsing.c:61)
    by 0x4089EF: parse_user (parsing.c:73)
    by 0x408D10: cgit_parse_commit (parsing.c:153)
    by 0x40A540: cgit_mk_refinfo (shared.c:171)
    by 0x40A581: cgit_refs_cb (shared.c:181)
    by 0x43DEB3: do_for_each_ref (refs.c:690)
    by 0x41075E: cgit_print_branches (ui-refs.c:191)
    by 0x416EF2: cgit_print_summary (ui-summary.c:56)
    by 0x40780A: summary_fn (cmd.c:120)
    by 0x40667A: process_request (cgit.c:544)
    by 0x404078: cache_process (cache.c:322)
  Address 0x4c718d0 is 0 bytes after a block of size 0 alloc'd
    at 0x4A0884D: malloc (vg_replace_malloc.c:263)
    by 0x455C85: xmalloc (wrapper.c:35)
    by 0x40894C: substr (parsing.c:60)
    by 0x4089EF: parse_user (parsing.c:73)
    by 0x408D10: cgit_parse_commit (parsing.c:153)
    by 0x40A540: cgit_mk_refinfo (shared.c:171)
    by 0x40A581: cgit_refs_cb (shared.c:181)
    by 0x43DEB3: do_for_each_ref (refs.c:690)
    by 0x41075E: cgit_print_branches (ui-refs.c:191)
    by 0x416EF2: cgit_print_summary (ui-summary.c:56)
    by 0x40780A: summary_fn (cmd.c:120)
    by 0x40667A: process_request (cgit.c:544)

 Invalid write of size 1
    at 0x4A09400: strncpy (mc_replace_strmem.c:463)
    by 0x408977: substr (parsing.c:61)
    by 0x4089EF: parse_user (parsing.c:73)
    by 0x408D10: cgit_parse_commit (parsing.c:153)
    by 0x40A540: cgit_mk_refinfo (shared.c:171)
    by 0x40A581: cgit_refs_cb (shared.c:181)
    by 0x43DEB3: do_for_each_ref (refs.c:690)
    by 0x41075E: cgit_print_branches (ui-refs.c:191)
    by 0x416EF2: cgit_print_summary (ui-summary.c:56)
    by 0x40780A: summary_fn (cmd.c:120)
    by 0x40667A: process_request (cgit.c:544)
    by 0x404078: cache_process (cache.c:322)
  Address 0x4c7192b is not stack'd, malloc'd or (recently) free'd

 Invalid write of size 1
    at 0x4A0940E: strncpy (mc_replace_strmem.c:463)
    by 0x408977: substr (parsing.c:61)
    by 0x4089EF: parse_user (parsing.c:73)
    by 0x408D10: cgit_parse_commit (parsing.c:153)
    by 0x40A540: cgit_mk_refinfo (shared.c:171)
    by 0x40A581: cgit_refs_cb (shared.c:181)
    by 0x43DEB3: do_for_each_ref (refs.c:690)
    by 0x41075E: cgit_print_branches (ui-refs.c:191)
    by 0x416EF2: cgit_print_summary (ui-summary.c:56)
    by 0x40780A: summary_fn (cmd.c:120)
    by 0x40667A: process_request (cgit.c:544)
    by 0x404078: cache_process (cache.c:322)
  Address 0x4c7192d is not stack'd, malloc'd or (recently) free'd

 Process terminating with default action of signal 11 (SIGSEGV)
  Access not within mapped region at address 0x502F000
    at 0x4A09400: strncpy (mc_replace_strmem.c:463)
    by 0x408977: substr (parsing.c:61)
    by 0x4089EF: parse_user (parsing.c:73)
    by 0x408D10: cgit_parse_commit (parsing.c:153)
    by 0x40A540: cgit_mk_refinfo (shared.c:171)
    by 0x40A581: cgit_refs_cb (shared.c:181)
    by 0x43DEB3: do_for_each_ref (refs.c:690)
    by 0x41075E: cgit_print_branches (ui-refs.c:191)
    by 0x416EF2: cgit_print_summary (ui-summary.c:56)
    by 0x40780A: summary_fn (cmd.c:120)
    by 0x40667A: process_request (cgit.c:544)
    by 0x404078: cache_process (cache.c:322)

This happens when tail - head == -1 here:
(parsing.c)

  char *substr(const char *head, const char *tail)
  {
          char *buf;

          buf = xmalloc(tail - head + 1);
          strncpy(buf, head, tail - head);
          buf[tail - head] = '\0';
          return buf;
  }

  char *parse_user(char *t, char **name, char **email, unsigned long *date)
  {
          char *p = t;
          int mode = 1;

          while (p && *p) {
                  if (mode == 1 && *p == '<') {
                          *name = substr(t, p - 1);
                          t = p;
                          mode++;
                  } else if (mode == 1 && *p == '\n') {

The fix is to handle the case of (tail < head) before calling xmalloc,
thus avoiding passing an invalid value to xmalloc.

And here's the reproducer:
It was tricky to reproduce, because git prohibits use of an empty "name"
in a commit ID.  To construct the offending commit, I had to resort to
using "git hash-object".

git init -q foo &&
( cd foo &&
  echo a > j && git add . && git ci -q --author='au <T at h.or>' -m. . &&
  h=$(git cat-file commit HEAD|sed 's/au //' \
    |git hash-object -t commit -w --stdin) &&
  git co -q -b test $h &&
  git br -q -D master &&
  git br -q -m test master)
git clone -q --bare foo foo.git

cat <<EOF > in
repo.url=foo.git
repo.path=foo.git
EOF
CGIT_CONFIG=in QUERY_STRING=url=foo.git valgrind ./cgit

The valgrind output is what you see above.

AFAICS, this is not exploitable thanks (ironically) to the use of strncpy.
Since that -1 translates to SIZE_MAX and this is strncpy, not only does it
copy whatever is in "head" (up to first NUL), but it also writes
SIZE_MAX - strlen(head) NUL bytes into the destination buffer, and that
latter is guaranteed to evoke a segfault.  Since cgit is single-threaded,
AFAICS, there is no way that the buffer clobbering can be turned into
an exploit.
2012-10-02 04:03:47 +02:00
Lukas Fleischer
1e25ac5b8f Remove dead initialization in cgit_parse_commit()
The value stored to "t" during its initialization gets overwritten in
any case, so just leave it uninitialized. Spotted by clang-analyzer.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2011-07-22 12:21:11 +00:00
Lukas Fleischer
a0bf375a1a Avoid null pointer dereference in reencode().
Returning "*txt" if "txt" is a null pointer is a bad thing. Spotted with
clang-analyzer.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2011-05-23 22:58:35 +02:00
Julius Plenz
0a799424f6 fix two encoding bugs
reencode() takes three arguments in the order (txt, from, to), opposed to
reencode_string, which will, like iconv, handle the arguments with from
and to swapped. Fix that (this makes reencode more intuitive).
If src and dst encoding are equivalent, don't do any encoding.

If no special encoding parameter is found within the commit, assume
UTF-8 and explicitly convert to PAGE_ENCODING. The change to reencode()
mentioned above avoids re-encoding a UTF-8 string to UTF-8, for example.

Signed-off-by: Julius Plenz <plenz@cis.fu-berlin.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2011-03-26 15:21:07 +01:00
Rémi Lagacé
73ac0fb6f2 Reencode author and committer
When a commit has a specific encoding, this encoding also applies to
the author and committer name and email.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2010-07-13 19:24:55 +02:00
Lars Hjemli
14b4e108a7 parsing.c: enable builds with NO_ICONV defined
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-12-05 19:10:28 +01:00
Lars Hjemli
a8305a9543 parsing.c: be prepared for unexpected content in commit/tag objects
When parsing commits and tags cgit made too many assumptions about the
formatting of said objects. This patch tries to make the code be more
prepared to handle 'malformed' objects.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-09-15 22:33:11 +02:00
Lars Hjemli
e87e896333 Move cgit_parse_query() from parsing.c to html.c as http_parse_querystring()
This is a generic http-function.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-04-08 21:11:36 +02:00
Lars Hjemli
20a33548b9 Move function for configfile parsing into configfile.[ch]
This is a generic function which wanted its own little object file.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-03-28 00:09:11 +01:00
Lars Hjemli
e0e4478e7b Add command dispatcher
This simplifies the code in cgit.c and makes it easier to extend cgit with
new pages/commands.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-03-24 01:43:48 +01:00
Lars Hjemli
d1f3bbe9d2 Move cgit_repo into cgit_context
This removes the global variable which is used to keep track of the
currently selected repository, and adds a new variable in the cgit_context
structure.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-02-16 13:56:09 +01:00
Lars Hjemli
d14d77fe95 Introduce struct cgit_context
This struct will hold all the cgit runtime information currently found in
a multitude of global variables.

The first cleanup removes all querystring-related variables.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2008-02-16 12:07:28 +01:00
Lars Hjemli
dabb34af76 Merge branch 'stable'
* stable:
  Handle missing timestamp in commit/tag objects
  Set commit date on snapshot contents
2007-12-02 22:28:37 +01:00
Lars Hjemli
fc4c4ba3a9 Handle missing timestamp in commit/tag objects
When a commit or tag lacks author/committer/tagger timestamp, do not skip
the next line in the commit/tag object.

Also, do not bother to print timestamps with value 0 as it is close to certain
to be bogus.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-12-02 22:27:07 +01:00
Lars Hjemli
a2ebbd6948 Use utf8::reencode_string from git
This replaces the iconv-support in cgit with similar functions already
existing in git.

Signed-off-by: Lars Hjemli <hjemli@gmai.com>
2007-11-05 18:13:31 -05:00
Jonathan Bastien-Filiatrault
7858a309d7 Convert subject and message with iconv_msg. 2007-11-05 18:13:31 -05:00
Jonathan Bastien-Filiatrault
af08198304 Add iconv_msg function. 2007-11-05 18:13:30 -05:00
Jonathan Bastien-Filiatrault
aa5cc328f4 Set msg_encoding according to the header. 2007-11-05 18:13:30 -05:00
Jonathan Bastien-Filiatrault
3845e177e4 Add commit->msg_encoding, allocate msg dynamicly. 2007-11-05 18:13:30 -05:00
Lars Hjemli
c61360fea0 cgit_parse_commit(): Add missing call to xstrdup()
It's rather silly to point into random memory-locations. Also, remove a
call to strdup() used on a literal char *.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-10-27 13:55:12 +02:00
Lars Hjemli
13d2b0b25c Skip unknown header fields when parsing tags and commits
Both the commit- and tagparser failed to handle unexpected header fields.
This adds futureproofing by simply skipping any header we don't know/care
about.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-10-27 09:05:40 +02:00
Lars Hjemli
382805ee83 Add trim_end() and use it to remove trailing slashes from repo paths
The new function removes all trailing instances of an arbitrary character
from a copy of the supplied char array. This is then used to remove any
trailing slashes from cgit_query_path.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-06-26 18:04:39 +02:00
Ondrej Jirman
6130231ed5 Check for NULL commit buffer in cgit_parse_commit()
This can be NULL, so try not to segfault.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-31 10:24:43 +02:00
Ondrej Jirman
3ce6fc16ef Handle single-line and empty commit subjects
If commit object ends with \0 after subject line, then info->subject
was not set.

This commit fixes this and also sets subject to ** empty ** if it
would otherwise be empty, so that there is something to click on.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-31 10:21:50 +02:00
Lars Hjemli
3de63b264c Don't be fooled by trailing '/' in url-parameter
cgit_parse_url() didn't check if the path-part of urls contained a
real path or just a trailing slash. This made the log-page die since
the path filtering supplied an invalid path argument. This fixes it.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-18 22:51:02 +02:00
Lars Hjemli
30ccdcaa74 Enable url=value querystring parameter
This makes is possible to use repo-urls like '/pub/scm/git/git.git' and
even add path specifications, like '/pub/scm/git/git.git/log/documentation'.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-18 22:51:01 +02:00
Lars Hjemli
47a81c77fd Restrict deep nesting of configfiles
There is no point in restricting the number of included config-
files, but there is a point in restricting the nestinglevel
of configfiles: to avoid recursive inclusions. This is easily
achieved by decrementing the static nesting-variable upon exit
from cgit_read_config().

Also fix some whitespace breakage.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-15 23:32:25 +02:00
Lars Hjemli
5ec6e02bd1 Add include-parameter to config files
This parameter can be used to include another config-file, like
a standalone repository listing.

Suggested in a patch by Kristian Høgsberg <krh@bitplanet.net>

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-14 23:40:33 +02:00
Lars Hjemli
61c3ca978c Update to libgit 1.5.2-rc2
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-05-08 23:38:49 +02:00
Lars Hjemli
ebd7b0fbc3 Do not die if tag has no message
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-02-04 21:21:46 +01:00
Lars Hjemli
a69061fdb7 Add function cgit_parse_tag()
Teach cgit how to extract author info from a tag.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2007-01-17 01:09:51 +01:00
Lars Hjemli
66091f934a Handle empty/malformed commit messages
An empty commit message would trigger a segfault in the current
cgit_parse_commit().

Also, make sure that all char-pointers are properly initialized.
2007-01-16 18:41:01 +01:00
Lars Hjemli
52e605caf5 Handle %xx encoding in querystring
Convert valid %xx expressions in querystring to ascii, ignore invalid
expressions (i.e. eat the three characters %xx).

Signed-off-by: Lars Hjemli <larsh@hal-2004.(none)>
2007-01-04 16:57:00 +01:00
Lars Hjemli
05b13194b4 Handle '+' in querystring
Translate '+' to ' ' in querystring parser (still doesn't handle %xx)

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2006-12-28 02:51:46 +01:00
Lars Hjemli
77078ba716 Teach commit parser about author/committer email + timestamp
We want all four of these when showing a commit, so save them in the
commitinfo struct.

Btw: There's probably no good reason to save committer timestamp since
it's already available in commit->date. But it doesn't hurt us either,
and it makes the parser look more complete, so we just do it.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2006-12-16 14:25:41 +01:00
Lars Hjemli
9a8f88658d Add ui-commit.c + misc ui cleanups
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2006-12-16 00:19:56 +01:00
Lars Hjemli
2101e26fd6 Add a common commit parser
Make a better commit parser, replacing the ugly one in ui-log.c

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2006-12-15 18:17:36 +01:00
Lars Hjemli
51ada4fda2 Rename config.c to parsing.c + move cgit_parse_query from cgit.c to parsing.c
Signed-off-by: Lars Hjemli <hjemli@gmail.com>
2006-12-11 16:11:40 +01:00