Re: git archive generates tar with malformed pax extended attribute
- From
René Scharfe <l.s.r@web.de>
- Date
- May 28, 2019, 23:34 UTC
- Message-ID
- <5f9ac691-4cb1-a15d-ca44-63fb64994d59@web.de>
- In-Reply-To
- <20190528190815.GA20499@sigill.intra.peff.net>
Am 28.05.19 um 21:08 schrieb Jeff King:
Show 20 quoted lines
> On Tue, May 28, 2019 at 08:01:43PM +0200, René Scharfe wrote: > >> Am 28.05.19 um 07:58 schrieb Jeff King: >>> On Sat, May 25, 2019 at 03:26:53PM +0200, René Scharfe wrote: >>> >>>> We could >>>> make git fsck report such symlinks. >>> >>> This is a little tricky, because fsck generally looks at individual >>> objects, and the bad pattern is a combination of a tree and a blob >>> together. I think you could make it work by reusing some of the code and >>> patterns from 9e84a6d758 (Merge branch 'jk/submodule-fsck-loose' into >>> maint, 2018-05-22). >> >> Actually it's super easy, barely an inconvenience (SCNR, watched a lot >> of those rants recently).. Did I miss something? > > Yes. You cannot rely on calling read_object_file() in real-time when the > fsck is being done by index-pack. The blob in question may be in the > pack you are indexing.
It figures.
So something like the patch below?
Parsing trees with symlinks twice is not ideal, but keeps the set structure simple -- a standard oidset suffices.
The global variables are ugly. Moving them into struct fsck_option would be possible, but not much better, as they aren't really options.
FSCK_MSG_MISSING_TREE_OBJECT has never been used before, it seems.
--- fsck.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++ t/t1450-fsck.sh | 13 +++++++++++ 2 files changed, 71 insertions(+)
diff --git a/fsck.c b/fsck.c index 4703f55561..a6e7d0b03f 100644 --- a/fsck.c +++ b/fsck.c @@ -19,6 +19,7 @@ static struct oidset gitmodules_found = OIDSET_INIT; static struct oidset gitmodules_done = OIDSET_INIT; +static struct oidset trees_with_symlinks = OIDSET_INIT; #define FSCK_FATAL -1 #define FSCK_INFO -2 @@ -49,6 +50,7 @@ static struct oidset gitmodules_done = OIDSET_INIT; FUNC(MISSING_PARENT, ERROR) \ FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \ FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \ + FUNC(MISSING_SYMLINK_OBJECT, ERROR) \ FUNC(MISSING_TAG, ERROR) \ FUNC(MISSING_TAG_ENTRY, ERROR) \ FUNC(MISSING_TAG_OBJECT, ERROR) \ @@ -58,6 +60,7 @@ static struct oidset gitmodules_done = OIDSET_INIT; FUNC(MISSING_TYPE_ENTRY, ERROR) \ FUNC(MULTIPLE_AUTHORS, ERROR) \ FUNC(TAG_OBJECT_NOT_TAG, ERROR) \ + FUNC(SYMLINK_OBJECT_NOT_BLOB, ERROR) \ FUNC(TREE_NOT_SORTED, ERROR) \ FUNC(UNKNOWN_TYPE, ERROR) \ FUNC(ZERO_PADDED_DATE, ERROR) \ @@ -78,6 +81,7 @@ static struct oidset gitmodules_done = OIDSET_INIT; FUNC(NULL_SHA1, WARN) \ FUNC(ZERO_PADDED_FILEMODE, WARN) \ FUNC(NUL_IN_COMMIT, WARN) \ + FUNC(NUL_IN_SYMLINK_TARGET, WARN) \ /* infos (reported as warnings, but ignored by default) */ \ FUNC(GITMODULES_PARSE, INFO) \ FUNC(BAD_TAG_NAME, INFO) \ @@ -578,6 +582,33 @@ static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, con return c1 < c2 ? 0 : TREE_UNORDERED; } +static int fsck_symlink(struct tree *tree, const char *name, + const struct object_id *oid, + struct fsck_options *options) +{ + int ret = 0; + enum object_type type; + unsigned long size; + void *buffer = read_object_file(oid, &type, &size); + + if (!buffer) + ret = report(options, &tree->object, + FSCK_MSG_MISSING_SYMLINK_OBJECT, + "cannot read blob object for symlink %s", name); + else if (type != OBJ_BLOB) + ret = report(options, &tree->object, + FSCK_MSG_SYMLINK_OBJECT_NOT_BLOB, + "expected blob got %s for symlink %s", + type_name(type), name); + else if (memchr(buffer, '\0', size)) + ret = report(options, &tree->object, + FSCK_MSG_NUL_IN_SYMLINK_TARGET, + "NUL in target of symlink %s", name); + + free(buffer); + return ret; +} + static int fsck_tree(struct tree *item, struct fsck_options *options) { int retval = 0; @@ -626,6 +657,8 @@ static int fsck_tree(struct tree *item, struct fsck_options *options) FSCK_MSG_GITMODULES_SYMLINK, ".gitmodules is a symbolic link"); } + if (S_ISLNK(mode)) + oidset_insert(&trees_with_symlinks, &item->object.oid); if (update_tree_entry_gently(&desc)) { retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree"); @@ -1118,8 +1151,33 @@ int fsck_finish(struct fsck_options *options) free(buf); } + oidset_iter_init(&trees_with_symlinks, &iter); + while ((oid = oidset_iter_next(&iter))) { + struct tree *tree; + struct tree_desc desc; + struct name_entry entry; + + tree = lookup_tree(the_repository, oid); + if (!tree) { + struct object *obj = lookup_unknown_object(oid->hash); + ret |= report(options, obj, + FSCK_MSG_MISSING_TREE_OBJECT, + "tree %s not found", oid_to_hex(oid)); + continue; + } + if (parse_tree(tree)) + continue; + if (init_tree_desc_gently(&desc, tree->buffer, tree->size)) + continue; + while (tree_entry_gently(&desc, &entry)) { + if (S_ISLNK(entry.mode)) + ret |= fsck_symlink(tree, entry.path, + &entry.oid, options); + } + } oidset_clear(&gitmodules_found); oidset_clear(&gitmodules_done); + oidset_clear(&trees_with_symlinks); return ret; } diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh index 0f268a3664..ce9501d063 100755 --- a/t/t1450-fsck.sh +++ b/t/t1450-fsck.sh @@ -822,4 +822,17 @@ test_expect_success 'detect corrupt index file in fsck' ' test_i18ngrep "bad index file" errors ' +test_expect_success 'detect NUL in symlink target' ' + test_when_finished "git update-ref -d refs/heads/nul_in_symlink" && + test_when_finished "remove_object \$commit" && + test_when_finished "remove_object \$tree" && + test_when_finished "remove_object \$blob" && + blob=$(echo fooQbar | q_to_nul | git hash-object -w --stdin) && + tree=$(echo "120000 blob $blob symlink" | git mktree) && + commit=$(git commit-tree $tree) && + git update-ref refs/heads/nul_in_symlink $commit && + git fsck 2>out && + test_i18ngrep "NUL in target of symlink" out +' + test_done -- 2.21.0