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| author | Johannes Schindelin <johannes.schindelin@gmx.de> | 2022-05-24 00:23:06 +0000 |
|---|---|---|
| committer | Johannes Schindelin <johannes.schindelin@gmx.de> | 2023-03-22 17:53:32 +0100 |
| commit | 321854ac464bbc85ff2afe089c4a56505a1c9e25 (patch) | |
| tree | c4ea38b96ab7e23378554707f700b5239088603a | |
| parent | 86f6f4fa91a9a2310c8f73528a86bf2c52d47fe4 (diff) | |
| download | git-321854ac464bbc85ff2afe089c4a56505a1c9e25.tar.gz | |
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
Technically, the pointer difference `end - start` _could_ be negative,
and when cast to an (unsigned) `size_t` that would cause problems. In
this instance, the symptom is:
dir.c: In function 'git_url_basename':
dir.c:3087:13: error: 'memchr' specified bound [9223372036854775808, 0]
exceeds maximum object size 9223372036854775807
[-Werror=stringop-overread]
CC ewah/bitmap.o
3087 | if (memchr(start, '/', end - start) == NULL
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
While it is a bit far-fetched to think that `end` (which is defined as
`repo + strlen(repo)`) and `start` (which starts at `repo` and never
steps beyond the NUL terminator) could result in such a negative
difference, GCC has no way of knowing that.
See also https://gcc.gnu.org/bugzilla//show_bug.cgi?id=85783.
Let's just add a safety check, primarily for GCC's benefit.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | builtin/clone.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/builtin/clone.c b/builtin/clone.c index c042b2e256..9ab17cab19 100644 --- a/builtin/clone.c +++ b/builtin/clone.c @@ -251,6 +251,15 @@ static char *guess_dir_name(const char *repo, int is_bundle, int is_bare) } /* + * It should not be possible to overflow `ptrdiff_t` by passing in an + * insanely long URL, but GCC does not know that and will complain + * without this check. + */ + if (end - start < 0) + die(_("No directory name could be guessed.\n" + "Please specify a directory on the command line")); + + /* * Strip trailing port number if we've got only a * hostname (that is, there is no dir separator but a * colon). This check is required such that we do not |