Rename variables in a function added in 0282f4dced (fsck: offer a
function to demote fsck errors to warnings, 2015-06-22).
It was needlessly confusing that it took a "msg_type" argument, but
then later declared another "msg_type" of a different type.
Let's rename that to "severity", and rename "id" to "msg_id" and
"msg_id" to "msg_id_str" etc. This will make a follow-up change
smaller.
While I'm at it properly indent the fsck_set_msg_type() argument list.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor code I recently changed in 1f3299fda9 (fsck: make
fsck_config() re-usable, 2021-01-05) so that I could use fsck's config
callback in mktag in 1f3299fda9 (fsck: make fsck_config() re-usable,
2021-01-05).
I don't know what I was thinking in structuring the code this way, but
it clearly makes no sense to have an fsck_config_internal() at all
just so it can get a fsck_options when git_config() already supports
passing along some void* data.
Let's just make use of that instead, which gets us rid of the two
wrapper functions, and brings fsck's common config callback in line
with other such reusable config callbacks.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The approach to "fsck" the incoming objects in "index-pack" is
attractive for performance reasons (we have them already in core,
inflated and ready to be inspected), but fundamentally cannot be
applied fully when we receive more than one pack stream, as a tree
object in one pack may refer to a blob object in another pack as
".gitmodules", when we want to inspect blobs that are used as
".gitmodules" file, for example. Teach "index-pack" to emit
objects that must be inspected later and check them in the calling
"fetch-pack" process.
* jt/transfer-fsck-across-packs:
fetch-pack: print and use dangling .gitmodules
fetch-pack: with packfile URIs, use index-pack arg
http-fetch: allow custom index-pack args
http: allow custom index-pack args
Teach index-pack to print dangling .gitmodules links after its "keep" or
"pack" line instead of declaring an error, and teach fetch-pack to check
such lines printed.
This allows the tree side of the .gitmodules link to be in one packfile
and the blob side to be in another without failing the fsck check,
because it is now fetch-pack which checks such objects after all
packfiles have been downloaded and indexed (and not index-pack on an
individual packfile, as it is before this commit).
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix "git fsck --name-objects" which apparently has not been used by
anybody who is motivated enough to report breakage.
* js/fsck-name-objects-fix:
fsck --name-objects: be more careful parsing generation numbers
t1450: robustify `remove_object()`
In 7b35efd734 (fsck_walk(): optionally name objects on the go,
2016-07-17), the `fsck` machinery learned to optionally name the
objects, so that it is easier to see what part of the repository is in a
bad shape, say, when objects are missing.
To save on complexity, this machinery uses a parser to determine the
name of a parent given a commit's name: any `~<n>` suffix is parsed and
the parent's name is formed from the prefix together with `~<n+1>`.
However, this parser has a bug: if it finds a suffix `<n>` that is _not_
`~<n>`, it will mistake the empty string for the prefix and `<n>` for
the generation number. In other words, it will generate a name of the
form `~<bogus-number>`.
Let's fix this.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Newline characters in the host and path part of git:// URL are
now forbidden.
* jk/forbid-lf-in-git-url:
fsck: reject .gitmodules git:// urls with newlines
git_connect_git(): forbid newlines in host and path
Newline characters in the host and path part of git:// URL are
now forbidden.
* jk/forbid-lf-in-git-url:
fsck: reject .gitmodules git:// urls with newlines
git_connect_git(): forbid newlines in host and path
The previous commit taught the clone/fetch client side to reject a
git:// URL with a newline in it. Let's also catch these when fscking a
.gitmodules file, which will give an earlier warning.
Note that it would be simpler to just complain about newline in _any_
URL, but an earlier tightening for http/ftp made sure we kept allowing
newlines for unknown protocols (and this is covered in the tests). So
we'll stick to that precedent.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change mktag's acceptance rules to accept an empty body without an
empty line after the header again. This fixes an ancient unintended
dregression in "mktag".
When "mktag" was introduced in ec4465adb3 (Add "tag" objects that can
be used to sign other objects., 2005-04-25) the input checks were much
looser. When it was documented it 6cfec03680 (mktag: minimally update
the description., 2007-06-10) it was clearly intended for this \n to
be optional:
The message, when [it] exists, is separated by a blank line from
the header.
But then in e0aaf781f6 (mktag.c: improve verification of tagger field
and tests, 2008-03-27) this was made an error, seemingly by
accident. It was just a result of the general header checks, and all
the tests after that patch have a trailing empty line (but did not
before).
Let's allow this again, and tweak the test semantics changed in
e0aaf781f6 to remove the redundant empty line. New tests added in
previous commits of mine already added an explicit test for allowing
the empty line between header and body.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the fsck_config() function from builtin/fsck.c to fsck.[ch]. This
allows for re-using it in other tools that expose fsck logic and want
to support its configuration variables.
A logical continuation of this change would be to use a common
function for all of {fetch,receive}.fsck.* and fsck.*. See
5d477a334a (fsck (receive-pack): allow demoting errors to warnings,
2015-06-22) and my own 1362df0d41 (fetch: implement fetch.fsck.*,
2018-07-27) for the relevant code.
However, those routines want to not parse the fsck.skipList into OIDs,
but rather pass them along with the --strict option to another
process. It would be possible to refactor that whole thing so we
support e.g. a "fetch." prefix, then just keep track of the skiplist
as a filename instead of parsing it, and learn to spew that all out
from our internal structures into something we can append to the
--strict option.
But instead I'm planning to re-use this in "mktag", which'll just
re-use these "fsck.*" variables as-is.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the validation logic in "mktag" to use fsck's fsck_tag()
instead of its own custom parser. Curiously the logic for both dates
back to the same commit[1]. Let's unify them so we're not maintaining
two sets functions to verify that a tag is OK.
The behavior of fsck_tag() and the old "mktag" code being removed here
is different in few aspects.
I think it makes sense to remove some of those checks, namely:
A. fsck only cares that the timezone matches [-+][0-9]{4}. The mktag
code disallowed values larger than 1400.
Yes there's currently no timezone with a greater offset[2], but
since we allow any number of non-offical timezones (e.g. +1234)
passing this through seems fine. Git also won't break in the
future if e.g. French Polynesia decides it needs to outdo the Line
Islands when it comes to timezone extravagance.
B. fsck allows missing author names such as "tagger <email>", mktag
wouldn't, but would allow e.g. "tagger [2 spaces] <email>" (but
not "tagger [1 space] <email>"). Now we allow all of these.
C. Like B, but "mktag" disallowed spaces in the <email> part, fsck
allows it.
In some ways fsck_tag() is stricter than "mktag" was, namely:
D. fsck disallows zero-padded dates, but mktag didn't care. So
e.g. the timestamp "0000000000 +0000" produces an error now. A
test in "t1006-cat-file.sh" relied on this, it's been changed to
use "hash-object" (without fsck) instead.
There was one check I deemed worth keeping by porting it over to
fsck_tag():
E. "mktag" did not allow any custom headers, and by extension (as an
empty commit is allowed) also forbade an extra stray trailing
newline after the headers it knew about.
Add a new check in the "ignore" category to fsck and use it. This
somewhat abuses the facility added in efaba7cc77 (fsck:
optionally ignore specific fsck issues completely, 2015-06-22).
This is somewhat of hack, but probably the least invasive change
we can make here. The fsck command will shuffle these categories
around, e.g. under --strict the "info" becomes a "warn" and "warn"
becomes "error". Existing users of fsck's (and others,
e.g. index-pack) --strict option rely on this.
So we need to put something into a category that'll be ignored by
all existing users of the API. Pretending that
fsck.extraHeaderEntry=error ("ignore" by default) was set serves
to do this for us.
1. ec4465adb3 (Add "tag" objects that can be used to sign other
objects., 2005-04-25)
2. https://en.wikipedia.org/wiki/List_of_UTC_time_offsets
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The check in "git fsck" to ensure that the tree objects are sorted
still had corner cases it missed unsorted entries.
* rs/fsck-duplicate-names-in-trees:
fsck: detect more in-tree d/f conflicts
t1450: demonstrate undetected in-tree d/f conflict
t1450: increase test coverage of in-tree d/f detection
fsck: fix a typo in a comment
If the conflict candidate file name from the top of the stack is not a
prefix of the current candiate directory then we can discard it as no
matching directory can come up later. But we are not done checking the
candidate directory -- the stack might still hold a matching file name,
so stay in the loop and check the next candidate file name.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git fsck" ensures that the paths recorded in tree objects are
sorted and without duplicates, but it failed to notice a case where
a blob is followed by entries that sort before a tree with the same
name. This has been corrected.
* rs/fsck-duplicate-names-in-trees:
fsck: report non-consecutive duplicate names in trees
Tree entries are sorted in path order, meaning that directory names get
a slash ('/') appended implicitly. Git fsck checks if trees contains
consecutive duplicates, but due to that ordering there can be
non-consecutive duplicates as well if one of them is a directory and the
other one isn't. Such a tree cannot be fully checked out.
Find these duplicates by recording candidate file names on a stack and
check candidate directory names against that stack to find matches.
Suggested-by: Brandon Williams <bwilliamseng@gmail.com>
Original-test-by: Brandon Williams <bwilliamseng@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Reviewed-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The config API made mixed uses of int and size_t types to represent
length of various pieces of text it parsed, which has been updated
to use the correct type (i.e. size_t) throughout.
* jk/config-use-size-t:
config: reject parsing of files over INT_MAX
config: use size_t to store parsed variable baselen
git_config_parse_key(): return baselen as size_t
config: drop useless length variable in write_pair()
parse_config_key(): return subsection len as size_t
remote: drop auto-strlen behavior of make_branch() and make_rewrite()
Git's URL parser interprets
https:///example.com/repo.git
to have no host and a path of "example.com/repo.git". Curl, on the
other hand, internally redirects it to https://example.com/repo.git. As
a result, until "credential: parse URL without host as empty host, not
unset", tricking a user into fetching from such a URL would cause Git to
send credentials for another host to example.com.
Teach fsck to block and detect .gitmodules files using such a URL to
prevent sharing them with Git versions that are not yet protected.
A relative URL in a .gitmodules file could also be used to trigger this.
The relative URL resolver used for .gitmodules does not normalize
sequences of slashes and can follow ".." components out of the path part
and to the host part of a URL, meaning that such a relative URL can be
used to traverse from a https://foo.example.com/innocent superproject to
a https:///attacker.example.com/exploit submodule. Fortunately,
redundant extra slashes in .gitmodules are rare, so we can catch this by
detecting one after a leading sequence of "./" and "../" components.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
libcurl permits making requests without a URL scheme specified. In
this case, it guesses the URL from the hostname, so I can run
git ls-remote http::ftp.example.com/path/to/repo
and it would make an FTP request.
Any user intentionally using such a URL is likely to have made a typo.
Unfortunately, credential_from_url is not able to determine the host and
protocol in order to determine appropriate credentials to send, and
until "credential: refuse to operate when missing host or protocol",
this resulted in another host's credentials being leaked to the named
host.
Teach credential_from_url_gently to consider such a URL to be invalid
so that fsck can detect and block gitmodules files with such URLs,
allowing server operators to avoid serving them to downstream users
running older versions of Git.
This also means that when such URLs are passed on the command line, Git
will print a clearer error so affected users can switch to the simpler
URL that explicitly specifies the host and protocol they intend.
One subtlety: .gitmodules files can contain relative URLs, representing
a URL relative to the URL they were cloned from. The relative URL
resolver used for .gitmodules can follow ".." components out of the path
part and past the host part of a URL, meaning that such a relative URL
can be used to traverse from a https://foo.example.com/innocent
superproject to a https::attacker.example.com/exploit submodule.
Fortunately a leading ':' in the first path component after a series of
leading './' and '../' components is unlikely to show up in other
contexts, so we can catch this by detecting that pattern.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
In 07259e74ec (fsck: detect gitmodules URLs with embedded newlines,
2020-03-11), git fsck learned to check whether URLs in .gitmodules could
be understood by the credential machinery when they are handled by
git-remote-curl.
However, the check is overbroad: it checks all URLs instead of only
URLs that would be passed to git-remote-curl. In principle a git:// or
file:/// URL does not need to follow the same conventions as an http://
URL; in particular, git:// and file:// protocols are not succeptible to
issues in the credential API because they do not support attaching
credentials.
In the HTTP case, the URL in .gitmodules does not always match the URL
that would be passed to git-remote-curl and the credential machinery:
Git's URL syntax allows specifying a remote helper followed by a "::"
delimiter and a URL to be passed to it, so that
git ls-remote http::https://example.com/repo.git
invokes git-remote-http with https://example.com/repo.git as its URL
argument. With today's checks, that distinction does not make a
difference, but for a check we are about to introduce (for empty URL
schemes) it will matter.
.gitmodules files also support relative URLs. To ensure coverage for the
https based embedded-newline attack, urldecode and check them directly
for embedded newlines.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
We return the length to a subset of a string using an "int *"
out-parameter. This is fine most of the time, as we'd expect config keys
to be relatively short, but it could behave oddly if we had a gigantic
config key. A more appropriate type is size_t.
Let's switch over, which lets our callers use size_t as appropriate
(they are bound by our type because they must pass the out-parameter as
a pointer). This is mostly just a cleanup to make it clear this code
handles long strings correctly. In practice, our config parser already
chokes on long key names (because of a similar int/size_t mixup!).
When doing an int/size_t conversion, we have to be careful that nobody
was trying to assign a negative value to the variable. I manually
confirmed that for each case here. They tend to just feed the result to
xmemdupz() or similar; in a few cases I adjusted the parameter types for
helper functions to make sure the size_t is preserved.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The credential protocol can't handle values with newlines. We already
detect and block any such URLs from being used with credential helpers,
but let's also add an fsck check to detect and block gitmodules files
with such URLs. That will let us notice the problem earlier when
transfer.fsckObjects is turned on. And in particular it will prevent bad
objects from spreading, which may protect downstream users running older
versions of Git.
We'll file this under the existing gitmodulesUrl flag, which covers URLs
with option injection. There's really no need to distinguish the exact
flaw in the URL in this context. Likewise, I've expanded the description
of t7416 to cover all types of bogus URLs.
* maint-2.22: (43 commits)
Git 2.22.2
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
...
* maint-2.21: (42 commits)
Git 2.21.1
mingw: sh arguments need quoting in more circumstances
mingw: fix quoting of empty arguments for `sh`
mingw: use MSYS2 quoting even when spawning shell scripts
mingw: detect when MSYS2's sh is to be spawned more robustly
t7415: drop v2.20.x-specific work-around
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
...
* maint-2.20: (36 commits)
Git 2.20.2
t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
...
* maint-2.19: (34 commits)
Git 2.19.3
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
...
* maint-2.18: (33 commits)
Git 2.18.2
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
...
* maint-2.17: (32 commits)
Git 2.17.3
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
...
This allows hosting providers to detect whether they are being used
to attack users using malicious 'update = !command' settings in
.gitmodules.
Since ac1fbbda20 (submodule: do not copy unknown update mode from
.gitmodules, 2013-12-02), in normal cases such settings have been
treated as 'update = none', so forbidding them should not produce any
collateral damage to legitimate uses. A quick search does not reveal
any repositories making use of this construct, either.
Reported-by: Joern Schneeweisz <jschneeweisz@gitlab.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
* maint-2.16: (31 commits)
Git 2.16.6
test-drop-caches: use `has_dos_drive_prefix()`
Git 2.15.4
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
...
* maint-2.14: (28 commits)
Git 2.14.6
mingw: handle `subst`-ed "DOS drives"
mingw: refuse to access paths with trailing spaces or periods
mingw: refuse to access paths with illegal characters
unpack-trees: let merged_entry() pass through do_add_entry()'s errors
quote-stress-test: offer to test quoting arguments for MSYS2 sh
t6130/t9350: prepare for stringent Win32 path validation
quote-stress-test: allow skipping some trials
quote-stress-test: accept arguments to test via the command-line
tests: add a helper to stress test argument quoting
mingw: fix quoting of arguments
Disallow dubiously-nested submodule git directories
protect_ntfs: turn on NTFS protection by default
path: also guard `.gitmodules` against NTFS Alternate Data Streams
is_ntfs_dotgit(): speed it up
mingw: disallow backslash characters in tree objects' file names
path: safeguard `.git` against NTFS Alternate Streams Accesses
clone --recurse-submodules: prevent name squatting on Windows
is_ntfs_dotgit(): only verify the leading segment
test-path-utils: offer to run a protectNTFS/protectHFS benchmark
...
The config setting `core.protectNTFS` is specifically designed to work
not only on Windows, but anywhere, to allow for repositories hosted on,
say, Linux servers to be protected against NTFS-specific attack vectors.
As a consequence, `is_ntfs_dotgit()` manually splits backslash-separated
paths (but does not do the same for paths separated by forward slashes),
under the assumption that the backslash might not be a valid directory
separator on the _current_ Operating System.
However, the two callers, `verify_path()` and `fsck_tree()`, are
supposed to feed only individual path segments to the `is_ntfs_dotgit()`
function.
This causes a lot of duplicate scanning (and very inefficient scanning,
too, as the inner loop of `is_ntfs_dotgit()` was optimized for
readability rather than for speed.
Let's simplify the design of `is_ntfs_dotgit()` by putting the burden of
splitting the paths by backslashes as directory separators on the
callers of said function.
Consequently, the `verify_path()` function, which already splits the
path by directory separators, now treats backslashes as directory
separators _explicitly_ when `core.protectNTFS` is turned on, even on
platforms where the backslash is _not_ a directory separator.
Note that we have to repeat some code in `verify_path()`: if the
backslash is not a directory separator on the current Operating System,
we want to allow file names like `\`, but we _do_ want to disallow paths
that are clearly intended to cause harm when the repository is cloned on
Windows.
The `fsck_tree()` function (the other caller of `is_ntfs_dotgit()`) now
needs to look for backslashes in tree entries' names specifically when
`core.protectNTFS` is turned on. While it would be tempting to
completely disallow backslashes in that case (much like `fsck` reports
names containing forward slashes as "full paths"), this would be
overzealous: when `core.protectNTFS` is turned on in a non-Windows
setup, backslashes are perfectly valid characters in file names while we
_still_ want to disallow tree entries that are clearly designed to
exploit NTFS-specific behavior.
This simplification will make subsequent changes easier to implement,
such as turning `core.protectNTFS` on by default (not only on Windows)
or protecting against attack vectors involving NTFS Alternate Data
Streams.
Incidentally, this change allows for catching malicious repositories
that contain tree entries of the form `dir\.gitmodules` already on the
server side rather than only on the client side (and previously only on
Windows): in contrast to `is_ntfs_dotgit()`, the
`is_ntfs_dotgitmodules()` function already expects the caller to split
the paths by directory separators.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We don't actually look at the tree struct in fsck_tree() beyond its oid
and type (which is obviously OBJ_TREE). Just taking an oid gives our
callers more flexibility to avoid creating a struct, and makes it clear
that we are fscking just what is in the buffer, not any pre-parsed bits
from the struct.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We don't actually look at the commit struct in fsck_commit() beyond its
oid and type (which is obviously OBJ_COMMIT). Just taking an oid gives
our callers more flexibility to avoid creating or parsing a struct, and
makes it clear that we are fscking just what is in the buffer, not any
pre-parsed bits from the struct.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We don't actually look at the tag struct in fsck_tag() beyond its oid
and type (which is obviously OBJ_TAG). Just taking an oid gives our
callers more flexibility to avoid creating or parsing a struct, and
makes it clear that we are fscking just what is in the buffer, not any
pre-parsed bits from the struct.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In fsck_commit() and fsck_tag(), we have local "oid" variables used for
parsing parent and tagged-object oids. Let's give these more specific
names in preparation for the functions taking an "oid" parameter for the
object we're checking.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We only need the oid and type to pass on to report(). Let's accept the
broken-out parameters to give our callers more flexibility.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The only thing we do with the struct is pass its oid and type to
report(). We can just take those explicitly, which gives our callers
more flexibility.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since fsck_blob() no longer requires us to have a "struct blob", we
don't need to create one. Which also means we don't need to worry about
handling the case that lookup_blob() returns NULL (we'll still catch
wrongly-identified blobs when we read the actual object contents and
type from disk).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We don't actually need any information from the object struct except its
oid (and the type, of course, but that's implicitly OBJ_BLOB). This
gives our callers more flexibility to drop the object structs, too.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The report() function really only cares about the oid and type of the
object, not the full object struct. Let's convert it to take those two
items separately, which gives our callers more flexibility.
This makes some already-long lines even longer. I've mostly left them,
as our eventual goal is to shrink these down as we continue refactoring
(e.g., "&item->object" becomes "&item->object.oid, item->object.type",
but will eventually shrink down to "oid, type").
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The skiplist is inherently an oidset, so we don't need a full object
struct. Let's take just the oid to give our callers more flexibility.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
None of the callbacks actually care about having a "struct object";
they're happy with just the oid and type information. So let's give
ourselves more flexibility to avoid having a "struct object" by just
passing the broken-down fields.
Note that the callback already takes a "type" field for the fsck message
type. We'll rename that to "msg_type" (and use "object_type" for the
object type) to make the distinction explicit.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We don't actually care about having object structs; we only need to look
up decorations by oid. Let's accept this more limited form, which will
give our callers more flexibility.
Note that the decoration API we rely on uses object structs itself (even
though it only looks at their oids). We can solve this by switching to
a kh_oid_map (we could also use the hashmap oidmap, but it's more
awkward for the simple case of just storing a void pointer).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This isolates the implementation detail of using the decoration code to
our put/get functions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 90cf590f53 (fsck: optionally show more helpful info for broken
links, 2016-07-17) added a system for decorating objects with names. The
code is split across builtin/fsck.c (which gives the initial names) and
fsck.c (which adds to the names as it traverses the object graph). This
leads to some duplication, where both sites have near-identical
describe_object() functions (the difference being that the one in
builtin/fsck.c uses a circular array of buffers to allow multiple calls
in a single printf).
Let's provide a unified object_name API for fsck. That lets us drop the
duplication, as well as making the interface boundaries more clear
(which will let us refactor the implementation more in a future patch).
We'll leave describe_object() in builtin/fsck.c as a thin wrapper around
the new API, as it relies on a static global to make its many callers a
bit shorter.
We'll also convert the bare add_decoration() calls in builtin/fsck.c to
put_object_name(). This fixes two minor bugs:
1. We leak many small strings. add_decoration() has a last-one-wins
approach: it updates the decoration to the new string and returns
the old one. But we ignore the return value, leaking the old
string. This is quite common to trigger, since we look at reflogs:
the tip of any ref will be described both by looking at the actual
ref, as well as the latest reflog entry. So we'd always end up
leaking one of those strings.
2. The last-one-wins approach gives us lousy names. For instance, we
first look at all of the refs, and then all of the reflogs. So
rather than seeing "refs/heads/master", we're likely to overwrite
it with "HEAD@{12345678}". We're generally better off using the
first name we find.
And indeed, the test in t1450 expects this ugly HEAD@{} name. After
this patch, we've switched to using fsck_put_object_name()'s
first-one-wins semantics, and we output the more human-friendly
"refs/tags/julius" (and the test is updated accordingly).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The fsck_object() function takes in a buffer, but also a "struct
object". The rules for using these vary between types:
- for a commit, we'll use the provided buffer; if it's NULL, we'll
fall back to get_commit_buffer(), which loads from either an
in-memory cache or from disk. If the latter fails, we'd die(), which
is non-ideal for fsck.
- for a tag, a NULL buffer will fall back to loading the object from
disk (and failure would lead to an fsck error)
- for a tree, we _never_ look at the provided buffer, and always use
tree->buffer
- for a blob, we usually don't look at the buffer at all, unless it
has been marked as a .gitmodule file. In that case we check the
buffer given to us, or assume a NULL buffer is a very large blob
(and complain about it)
This is much more complex than it needs to be. It turns out that nobody
ever feeds a NULL buffer that isn't a blob:
- git-fsck calls fsck_object() only from fsck_obj(). That in turn is
called by one of:
- fsck_obj_buffer(), which is a callback to verify_pack(), which
unpacks everything except large blobs into a buffer (see
pack-check.c, lines 131-141).
- fsck_loose(), which hits a BUG() on non-blobs with a NULL buffer
(builtin/fsck.c, lines 639-640)
And in either case, we'll have just called parse_object_buffer()
anyway, which would segfault on a NULL buffer for commits or tags
(not for trees, but it would install a NULL tree->buffer which would
later cause a segfault)
- git-index-pack asserts that the buffer is non-NULL unless the object
is a blob (see builtin/index-pack.c, line 832)
- git-unpack-objects always writes a non-NULL buffer into its
obj_buffer hash, which is then fed to fsck_object(). (There is
actually a funny thing here where it does not store blob buffers at
all, nor does it call fsck on them; it does check any needed blobs
via fsck_finish() though).
Let's make the rules simpler, which reduces the amount of code and gives
us more flexibility in refactoring the fsck code. The new rules are:
- only blobs are allowed to pass a NULL buffer
- we always use the provided buffer, never pulling information from
the object struct
We don't have to adjust any callers, because they were already adhering
to these. Note that we do drop a few fsck identifiers for missing tags,
but that was all dead code (because nobody passed a NULL tag buffer).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Way back in 92d4c85d24 (fsck-cache: fix SIGSEGV on bad tag object,
2005-05-03), we added an fsck check that the "tagged" field of a tag
struct isn't NULL. But that was mainly protecting the printing code for
"--tags", and that code wasn't moved along with the check as part of
ba002f3b28 (builtin-fsck: move common object checking code to fsck.c,
2008-02-25).
It could also serve to detect type mismatch problems (where a tag points
to object X as a commit, but really X is a blob), but it couldn't do so
reliably (we'd call lookup_commit(X), but it will only notice the
problem if we happen to have previously called lookup_blob(X) in the
same process). And as of a commit earlier in this series, we'd consider
that a parse error and complain about the object even before getting to
this point anyway.
So let's drop this "tag->tagged" check. It's not helping anything, and
getting rid of it makes the function conceptually cleaner, as it really
is just checking the buffer we feed it. In fact, we can get rid of our
one-line wrapper and just unify fsck_tag() and fsck_tag_buffer().
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 4516338243 (builtin-fsck: reports missing parent commits,
2008-02-25), we added code to check that fsck found the same number of
parents from parsing the commit itself as we see in the commit struct we
got from parse_commit_buffer(). Back then the rationale was that the
normal commit parser might skip some bad parents.
But earlier in this series, we started treating that reliably as a
parsing error, meaning that we'd complain about it before we even hit
the code in fsck.c.
Let's drop this code, which now makes fsck_commit_buffer() completely
independent of any parsed values in the commit struct (that's
conceptually cleaner, and also opens up more refactoring options).
Note that we can also drop the MISSING_PARENT and MISSING_GRAFT fsck
identifiers. This is no loss, as these would not trigger reliably
anyway. We'd hit them only when lookup_commit() failed, which occurs
only if we happen to have seen the object with another type already in
the same process. In most cases, we'd actually run into the problem
during the connectivity walk, not here.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We check in fsck_commit_buffer() that commit->tree isn't NULL, which in
turn generally comes from a previous parse by parse_commit(). But this
isn't really accomplishing anything. The two things we might care about
are:
- was there a syntactically valid "tree <oid>" line in the object? But
we've just done our own parse in fsck_commit_buffer() to check this.
- does it point to a valid tree object? But checking the "tree"
pointer here doesn't actually accomplish that; it just shows that
lookup_tree() didn't return NULL, which only means that we haven't
yet seen that oid as a non-tree in this process.
A real connectivity check would exhaustively walk all graph links,
and we do that already in a separate function.
So this code isn't helping anything. And it makes the fsck code slightly
more confusing and rigid (e.g., it requires that any commit structs have
already been parsed). Let's drop it.
As a bit of history, the presence of this code looks like a leftover
from early fsck code (which did rely on parse_commit() to do most of the
parsing). The check comes from ff5ebe39b0 (Port fsck-cache to use
parsing functions, 2005-04-18), but we later added an explicit walk in
355885d531 (add generic, type aware object chain walker, 2008-02-25).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git blame" learned to "ignore" commits in the history, whose
effects (as well as their presence) get ignored.
* br/blame-ignore:
t8014: remove unnecessary braces
blame: drop some unused function parameters
blame: add a test to cover blame_coalesce()
blame: use the fingerprint heuristic to match ignored lines
blame: add a fingerprint heuristic to match ignored lines
blame: optionally track line fingerprints during fill_blame_origin()
blame: add config options for the output of ignored or unblamable lines
blame: add the ability to ignore commits and their changes
blame: use a helper function in blame_chunk()
Move oidset_parse_file() to oidset.c
fsck: rename and touch up init_skiplist()
There are no callers left of lookup_unknown_object() that aren't just
passing us the "hash" member of a "struct object_id". Let's take the
whole struct, which gets us closer to removing all raw sha1 variables.
It also matches the existing conversions of lookup_blob(), etc.
The conversions of callers were done by hand, but they're all mechanical
one-liners.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
init_skiplist() took a file consisting of SHA-1s and comments and added
the objects to an oidset. This functionality is useful for other
commands and will be moved to oidset.c in a future commit.
In preparation for that move, this commit renames it to
oidset_parse_file() to reflect its more generic usage and cleans up a
few of the names.
Signed-off-by: Barret Rhoden <brho@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
struct diff_filespec defines mode to be an 'unsigned short'. Several
other places in the API which we'd like to interact with using a
diff_filespec used a plain unsigned (or unsigned int). This caused
problems when taking addresses, so switch to unsigned short.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When parsing a tree, we read the object ID directly out of the tree
buffer. This is normally fine, but such an object ID cannot be used with
oidcpy, which copies GIT_MAX_RAWSZ bytes, because if we are using SHA-1,
there may not be that many bytes to copy.
Instead, store the object ID in a separate struct member. Since we can
no longer efficiently compute the path length, store that information as
well in struct name_entry. Ensure we only copy the object ID into the
new buffer if the path length is nonzero, as some callers will pass us
an empty path with no object ID following it, and we will not want to
read past the end of the buffer.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update fsck.skipList implementation and documentation.
* ab/fsck-skiplist:
fsck: support comments & empty lines in skipList
fsck: use oidset instead of oid_array for skipList
fsck: use strbuf_getline() to read skiplist file
fsck: add a performance test for skipList
fsck: add a performance test
fsck: document that skipList input must be unabbreviated
fsck: document and test commented & empty line skipList input
fsck: document and test sorted skipList input
fsck tests: add a test for no skipList input
fsck tests: setup of bogus commit object
* maint-2.18:
Git 2.18.1
Git 2.17.2
fsck: detect submodule paths starting with dash
fsck: detect submodule urls starting with dash
Git 2.16.5
Git 2.15.3
Git 2.14.5
submodule-config: ban submodule paths that start with a dash
submodule-config: ban submodule urls that start with dash
submodule--helper: use "--" to signal end of clone options
* maint-2.17:
Git 2.17.2
fsck: detect submodule paths starting with dash
fsck: detect submodule urls starting with dash
Git 2.16.5
Git 2.15.3
Git 2.14.5
submodule-config: ban submodule paths that start with a dash
submodule-config: ban submodule urls that start with dash
submodule--helper: use "--" to signal end of clone options
As with urls, submodule paths with dashes are ignored by
git, but may end up confusing older versions. Detecting them
via fsck lets us prevent modern versions of git from being a
vector to spread broken .gitmodules to older versions.
Compared to blocking leading-dash urls, though, this
detection may be less of a good idea:
1. While such paths provide confusing and broken results,
they don't seem to actually work as option injections
against anything except "cd". In particular, the
submodule code seems to canonicalize to an absolute
path before running "git clone" (so it passes
/your/clone/-sub).
2. It's more likely that we may one day make such names
actually work correctly. Even after we revert this fsck
check, it will continue to be a hassle until hosting
servers are all updated.
On the other hand, it's not entirely clear that the behavior
in older versions is safe. And if we do want to eventually
allow this, we may end up doing so with a special syntax
anyway (e.g., writing "./-sub" in the .gitmodules file, and
teaching the submodule code to canonicalize it when
comparing).
So on balance, this is probably a good protection.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Urls with leading dashes can cause mischief on older
versions of Git. We should detect them so that they can be
rejected by receive.fsckObjects, preventing modern versions
of git from being a vector by which attacks can spread.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's annoying not to be able to put comments and empty lines in the
skipList, when e.g. keeping a big central list of commits to skip in
/etc/gitconfig, which was my motivation for 1362df0d41 ("fetch:
implement fetch.fsck.*", 2018-07-27).
Implement that, and document what version of Git this was changed in,
since this on-disk format can be expected to be used by multiple
versions of git.
There is no notable performance impact from this change, using the
test setup described a couple of commits back:
Test HEAD~ HEAD
----------------------------------------------------------------------------------------
1450.3: fsck with 0 skipped bad commits 7.69(7.27+0.42) 7.86(7.48+0.37) +2.2%
1450.5: fsck with 1 skipped bad commits 7.69(7.30+0.38) 7.83(7.47+0.36) +1.8%
1450.7: fsck with 10 skipped bad commits 7.76(7.38+0.38) 7.79(7.38+0.41) +0.4%
1450.9: fsck with 100 skipped bad commits 7.76(7.38+0.38) 7.74(7.36+0.38) -0.3%
1450.11: fsck with 1000 skipped bad commits 7.71(7.30+0.41) 7.72(7.34+0.38) +0.1%
1450.13: fsck with 10000 skipped bad commits 7.74(7.34+0.40) 7.72(7.34+0.38) -0.3%
1450.15: fsck with 100000 skipped bad commits 7.75(7.40+0.35) 7.70(7.29+0.40) -0.6%
1450.17: fsck with 1000000 skipped bad commits 7.12(6.86+0.26) 7.13(6.87+0.26) +0.1%
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the implementation of the skipList feature to use oidset
instead of oid_array to store SHA-1s for later lookup.
This list is parsed once on startup by fsck, fetch-pack or
receive-pack depending on the *.skipList config in use. I.e. only once
per invocation, but note that for "clone --recurse-submodules" each
submodule will re-parse the list, in addition to the main project, and
it will be re-parsed when checking .gitmodules blobs, see
fb16287719 ("fsck: check skiplist for object in fsck_blob()",
2018-06-27).
Memory usage is a bit higher, but we don't need to keep track of the
sort order anymore. Embed the oidset into struct fsck_options to make
its ownership clear (no hidden sharing) and avoid unnecessary pointer
indirection.
The cumulative impact on performance of this & the preceding change,
using the test setup described in the previous commit:
Test HEAD~2 HEAD~ HEAD
----------------------------------------------------------------------------------------------------------------
1450.3: fsck with 0 skipped bad commits 7.70(7.31+0.38) 7.72(7.33+0.38) +0.3% 7.70(7.30+0.40) +0.0%
1450.5: fsck with 1 skipped bad commits 7.84(7.47+0.37) 7.69(7.32+0.36) -1.9% 7.71(7.29+0.41) -1.7%
1450.7: fsck with 10 skipped bad commits 7.81(7.40+0.40) 7.94(7.57+0.36) +1.7% 7.92(7.55+0.37) +1.4%
1450.9: fsck with 100 skipped bad commits 7.81(7.42+0.38) 7.95(7.53+0.41) +1.8% 7.83(7.42+0.41) +0.3%
1450.11: fsck with 1000 skipped bad commits 7.99(7.62+0.36) 7.90(7.50+0.40) -1.1% 7.86(7.49+0.37) -1.6%
1450.13: fsck with 10000 skipped bad commits 7.98(7.57+0.40) 7.94(7.53+0.40) -0.5% 7.90(7.45+0.44) -1.0%
1450.15: fsck with 100000 skipped bad commits 7.97(7.57+0.39) 8.03(7.67+0.36) +0.8% 7.84(7.43+0.41) -1.6%
1450.17: fsck with 1000000 skipped bad commits 7.72(7.22+0.50) 7.28(7.07+0.20) -5.7% 7.13(6.87+0.25) -7.6%
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The buffer is unlikely to contain a NUL character, so printing its
contents using %s in a die() format is unsafe (detected with ASan).
Use an idiomatic strbuf_getline() loop instead, which ensures the buffer
is always NUL-terminated, supports CRLF files as well, accepts files
without a newline after the last line, supports any hash length
automatically, and is shorter.
This fixes a bug where emitting an error about an invalid line on say
line 1 would continue printing subsequent lines, and usually continue
into uninitialized memory.
The performance impact of this, on a CentOS 7 box with RedHat GCC
4.8.5-28:
$ GIT_PERF_REPEAT_COUNT=5 GIT_PERF_MAKE_OPTS='-j56 CFLAGS="-O3"' ./run HEAD~ HEAD p1451-fsck-skip-list.sh
Test HEAD~ HEAD
----------------------------------------------------------------------------------------
1450.3: fsck with 0 skipped bad commits 7.75(7.39+0.35) 7.68(7.29+0.39) -0.9%
1450.5: fsck with 1 skipped bad commits 7.70(7.30+0.40) 7.80(7.42+0.37) +1.3%
1450.7: fsck with 10 skipped bad commits 7.77(7.37+0.40) 7.87(7.47+0.40) +1.3%
1450.9: fsck with 100 skipped bad commits 7.82(7.41+0.40) 7.88(7.43+0.44) +0.8%
1450.11: fsck with 1000 skipped bad commits 7.88(7.49+0.39) 7.84(7.43+0.40) -0.5%
1450.13: fsck with 10000 skipped bad commits 8.02(7.63+0.39) 8.07(7.67+0.39) +0.6%
1450.15: fsck with 100000 skipped bad commits 8.01(7.60+0.41) 8.08(7.70+0.38) +0.9%
1450.17: fsck with 1000000 skipped bad commits 7.60(7.10+0.50) 7.37(7.18+0.19) -3.0%
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recent "security fix" to pay attention to contents of ".gitmodules"
while accepting "git push" was a bit overly strict than necessary,
which has been adjusted.
* jk/fsck-gitmodules-gently:
fsck: downgrade gitmodulesParse default to "info"
fsck: split ".gitmodules too large" error from parse failure
fsck: silence stderr when parsing .gitmodules
config: add options parameter to git_config_from_mem
config: add CONFIG_ERROR_SILENT handler
config: turn die_on_error into caller-facing enum
"fsck.skipList" did not prevent a blob object listed there from
being inspected for is contents (e.g. we recently started to
inspect the contents of ".gitmodules" for certain malicious
patterns), which has been corrected.
* rj/submodule-fsck-skip:
fsck: check skiplist for object in fsck_blob()
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.
* sb/object-store-grafts:
commit: allow lookup_commit_graft to handle arbitrary repositories
commit: allow prepare_commit_graft to handle arbitrary repositories
shallow: migrate shallow information into the object parser
path.c: migrate global git_path_* to take a repository argument
cache: convert get_graft_file to handle arbitrary repositories
commit: convert read_graft_file to handle arbitrary repositories
commit: convert register_commit_graft to handle arbitrary repositories
commit: convert commit_graft_pos() to handle arbitrary repositories
shallow: add repository argument to is_repository_shallow
shallow: add repository argument to check_shallow_file_for_update
shallow: add repository argument to register_shallow
shallow: add repository argument to set_alternate_shallow_file
commit: add repository argument to lookup_commit_graft
commit: add repository argument to prepare_commit_graft
commit: add repository argument to read_graft_file
commit: add repository argument to register_commit_graft
commit: add repository argument to commit_graft_pos
object: move grafts to object parser
object-store: move object access functions to object-store.h
We added an fsck check in ed8b10f631 (fsck: check
.gitmodules content, 2018-05-02) as a defense against the
vulnerability from 0383bbb901 (submodule-config: verify
submodule names as paths, 2018-04-30). With the idea that
up-to-date hosting sites could protect downstream unpatched
clients that fetch from them.
As part of that defense, we reject any ".gitmodules" entry
that is not syntactically valid. The theory is that if we
cannot even parse the file, we cannot accurately check it
for vulnerabilities. And anybody with a broken .gitmodules
file would eventually want to know anyway.
But there are a few reasons this is a bad tradeoff in
practice:
- for this particular vulnerability, the client has to be
able to parse the file. So you cannot sneak an attack
through using a broken file, assuming the config parsers
for the process running fsck and the eventual victim are
functionally equivalent.
- a broken .gitmodules file is not necessarily a problem.
Our fsck check detects .gitmodules in _any_ tree, not
just at the root. And the presence of a .gitmodules file
does not necessarily mean it will be used; you'd have to
also have gitlinks in the tree. The cgit repository, for
example, has a file named .gitmodules from a
pre-submodule attempt at sharing code, but does not
actually have any gitlinks.
- when the fsck check is used to reject a push, it's often
hard to work around. The pusher may not have full control
over the destination repository (e.g., if it's on a
hosting server, they may need to contact the hosting
site's support). And the broken .gitmodules may be too
far back in history for rewriting to be feasible (again,
this is an issue for cgit).
So we're being unnecessarily restrictive without actually
improving the security in a meaningful way. It would be more
convenient to downgrade this check to "info", which means
we'd still comment on it, but not reject a push. Site admins
can already do this via config, but we should ship sensible
defaults.
There are a few counterpoints to consider in favor of
keeping the check as an error:
- the first point above assumes that the config parsers for
the victim and the fsck process are equivalent. This is
pretty true now, but as time goes on will become less so.
Hosting sites are likely to upgrade their version of Git,
whereas vulnerable clients will be stagnant (if they did
upgrade, they'd cease to be vulnerable!). So in theory we
may see drift over time between what two config parsers
will accept.
In practice, this is probably OK. The config format is
pretty established at this point and shouldn't change a
lot. And the farther we get from the announcement of the
vulnerability, the less interesting this extra layer of
protection becomes. I.e., it was _most_ valuable on day
0, when everybody's client was still vulnerable and
hosting sites could protect people. But as time goes on
and people upgrade, the population of vulnerable clients
becomes smaller and smaller.
- In theory this could protect us from other
vulnerabilities in the future. E.g., .gitmodules are the
only way for a malicious repository to feed data to the
config parser, so this check could similarly protect
clients from a future (to-be-found) bug there.
But that's trading a hypothetical case for real-world
pain today. If we do find such a bug, the hosting site
would need to be updated to fix it, too. At which point
we could figure out whether it's possible to detect
_just_ the malicious case without hurting existing
broken-but-not-evil cases.
- Until recently, we hadn't made any restrictions on
.gitmodules content. So now in tightening that we're
hitting cases where certain things used to work, but
don't anymore. There's some moderate pain now. But as
time goes on, we'll see more (and more varied) cases that
will make tightening harder in the future. So there's
some argument for putting rules in place _now_, before
users grow more cases that violate them.
Again, this is trading pain now for hypothetical benefit
in the future. And if we try hard in the future to keep
our tightening to a minimum (i.e., rejecting true
maliciousness without hurting broken-but-not-evil repos),
then that reduces even the hypothetical benefit.
Considering both sets of arguments, it makes sense to loosen
this check for now.
Note that we have to tweak the test in t7415 since fsck will
no longer consider this a fatal error. But we still check
that it reports the warning, and that we don't get the
spurious error from the config code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since ed8b10f631 (fsck: check .gitmodules content,
2018-05-02), we'll report a gitmodulesParse error for two
conditions:
- a .gitmodules entry is not syntactically valid
- a .gitmodules entry is larger than core.bigFileThreshold
with the intent that we can detect malicious files and
protect downstream clients. E.g., from the issue in
0383bbb901 (submodule-config: verify submodule names as
paths, 2018-04-30).
But these conditions are actually quite different with
respect to that bug:
- a syntactically invalid file cannot trigger the problem,
as the victim would barf before hitting the problematic
code
- a too-big .gitmodules _can_ trigger the problem. Even
though it is obviously silly to have a 500MB .gitmodules
file, the submodule code will happily parse it if you
have enough memory.
So it may be reasonable to configure their severity
separately. Let's add a new class for the "too large" case
to allow that.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since commit ed8b10f631 ("fsck: check .gitmodules content", 2018-05-02),
fsck will issue an error message for '.gitmodules' content that cannot
be parsed correctly. This is the case, even when the corresponding blob
object has been included on the skiplist. For example, using the cgit
repository, we see the following:
$ git fsck
Checking object directories: 100% (256/256), done.
error: bad config line 5 in blob .gitmodules
error in blob 51dd1eff1edc663674df9ab85d2786a40f7ae3a5: gitmodulesParse: could not parse gitmodules blob
Checking objects: 100% (6626/6626), done.
$
$ git config fsck.skiplist '.git/skip'
$ echo 51dd1eff1edc663674df9ab85d2786a40f7ae3a5 >.git/skip
$
$ git fsck
Checking object directories: 100% (256/256), done.
error: bad config line 5 in blob .gitmodules
Checking objects: 100% (6626/6626), done.
$
Note that the error message issued by the config parser is still
present, despite adding the object-id of the blob to the skiplist.
One solution would be to provide a means of suppressing the messages
issued by the config parser. However, given that (logically) we are
asking fsck to ignore this object, a simpler approach is to just not
call the config parser if the object is to be skipped. Add a check to
the 'fsck_blob()' processing function, to determine if the object is
on the skiplist and, if so, exit the function early.
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If there's a parsing error we'll already report it via the
usual fsck report() function (or not, if the user has asked
to skip this object or warning type). The error message from
the config parser just adds confusion. Let's suppress it.
Note that we didn't test this case at all, so I've added
coverage in t7415. We may end up toning down or removing
this fsck check in the future. So take this test as checking
what happens now with a focus on stderr, and not any
ironclad guarantee that we must detect and report parse
failures in the future.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The underlying config parser knows how to handle a
config_options struct, but git_config_from_mem() always
passes NULL. Let's allow our callers to specify the options
struct.
We could add a "_with_options" variant, but since there are
only a handful of callers, let's just update them to pass
NULL.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of lookup_tree
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of lookup_blob
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of parse_object
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continuing with the idea to programatically enumerate various
pieces of data required for command line completion, teach the
codebase to report the list of configuration variables
subcommands care about to help complete them.
* nd/complete-config-vars:
completion: complete general config vars in two steps
log-tree: allow to customize 'grafted' color
completion: support case-insensitive config vars
completion: keep other config var completion in camelCase
completion: drop the hard coded list of config vars
am: move advice.amWorkDir parsing back to advice.c
advice: keep config name in camelCase in advice_config[]
fsck: produce camelCase config key names
help: add --config to list all available config
fsck: factor out msg_id_info[] lazy initialization code
grep: keep all colors in an array
Add and use generic name->id mapping code for color slot parsing
Finishing touches to a topic that already is in 'maint'.
* jk/submodule-fsck-loose-fixup:
fsck: avoid looking at NULL blob->object
t7415: don't bother creating commit for symlink test
Commit 159e7b080b (fsck: detect gitmodules files,
2018-05-02) taught fsck to look at the content of
.gitmodules files. If the object turns out not to be a blob
at all, we just complain and punt on checking the content.
And since this was such an obvious and trivial code path, I
didn't even bother to add a test.
Except it _does_ do one non-trivial thing, which is call the
report() function, which wants us to pass a pointer to a
"struct object". Which we don't have (we have only a "struct
object_id"). So we erroneously pass a NULL object to
report(), which gets dereferenced and causes a segfault.
It seems like we could refactor report() to just take the
object_id itself. But we pass the object pointer along to
a callback function, and indeed this ends up in
builtin/fsck.c's objreport() which does want to look at
other parts of the object (like the type).
So instead, let's just use lookup_unknown_object() to get
the real "struct object", and pass that.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (42 commits)
merge-one-file: compute empty blob object ID
add--interactive: compute the empty tree value
Update shell scripts to compute empty tree object ID
sha1_file: only expose empty object constants through git_hash_algo
dir: use the_hash_algo for empty blob object ID
sequencer: use the_hash_algo for empty tree object ID
cache-tree: use is_empty_tree_oid
sha1_file: convert cached object code to struct object_id
builtin/reset: convert use of EMPTY_TREE_SHA1_BIN
builtin/receive-pack: convert one use of EMPTY_TREE_SHA1_HEX
wt-status: convert two uses of EMPTY_TREE_SHA1_HEX
submodule: convert several uses of EMPTY_TREE_SHA1_HEX
sequencer: convert one use of EMPTY_TREE_SHA1_HEX
merge: convert empty tree constant to the_hash_algo
builtin/merge: switch tree functions to use object_id
builtin/am: convert uses of EMPTY_TREE_SHA1_BIN to the_hash_algo
sha1-file: add functions for hex empty tree and blob OIDs
builtin/receive-pack: avoid hard-coded constants for push certs
diff: specify abbreviation size in terms of the_hash_algo
upload-pack: replace use of several hard-coded constants
...
