A fix to a minor regression to "git fsck" in v2.2 era that started
complaining about a body-less tag object when it lacks a separator
empty line after its header to separate it with a non-existent body.
* jc/fsck-retire-require-eoh:
fsck: it is OK for a tag and a commit to lack the body
When fsck validates a commit or a tag, it scans each line in the
header of the object using helper functions such as "start_with()",
etc. that work on a NUL terminated buffer, but before a1e920a0
(index-pack: terminate object buffers with NUL, 2014-12-08), the
validation functions were fed the object data in a piece of memory
that is not necessarily terminated with a NUL.
We added a helper function require_end_of_header() to be called at
the beginning of these validation functions to insist that the
object data contains an empty line before its end. The theory is
that the validating functions will notice and stop when it hits an
empty line as a normal end of header (or a required header line that
is missing) without scanning past the end of potentially not
NUL-terminated buffer.
But the theory forgot that in the older days, Git itself happily
created objects with only the header lines without a body. This
caused Git 2.2 and later to issue an unnecessary warning in some
existing repositories.
With a1e920a0, we do not need to require an empty line (or the body)
in these objects to safely parse and validate them. Drop the
offending "must have an empty line" check from this helper function,
while keeping the other check to make sure that there is no NUL in
the header part of the object, and adjust the name of the helper to
what it does accordingly.
Noticed-by: Wolfgang Denk <wd@denx.de>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
New tag object format validation added in 2.2 showed garbage
after a tagname it reported in its error message.
* js/fsck-tag-validation:
index-pack: terminate object buffers with NUL
fsck: properly bound "invalid tag name" error message
Now that the index can block pathnames that can be mistaken
to mean ".git" on NTFS and FAT32, it would be helpful for
fsck to notice such problematic paths. This lets servers
which use receive.fsckObjects block them before the damage
spreads.
Note that the fsck check is always on, even for systems
without core.protectNTFS set. This is technically more
restrictive than we need to be, as a set of users on ext4
could happily use these odd filenames without caring about
NTFS.
However, on balance, it's helpful for all servers to block
these (because the paths can be used for mischief, and
servers which bother to fsck would want to stop the spread
whether they are on NTFS themselves or not), and hardly
anybody will be affected (because the blocked names are
variants of .git or git~1, meaning mischief is almost
certainly what the tree author had in mind).
Ideally these would be controlled by a separate
"fsck.protectNTFS" flag. However, it would be much nicer to
be able to enable/disable _any_ fsck flag individually, and
any scheme we choose should match such a system. Given the
likelihood of anybody using such a path in practice, it is
not unreasonable to wait until such a system materializes.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the index can block pathnames that case-fold to
".git" on HFS+, it would be helpful for fsck to notice such
problematic paths. This lets servers which use
receive.fsckObjects block them before the damage spreads.
Note that the fsck check is always on, even for systems
without core.protectHFS set. This is technically more
restrictive than we need to be, as a set of users on ext4
could happily use these odd filenames without caring about
HFS+.
However, on balance, it's helpful for all servers to block
these (because the paths can be used for mischief, and
servers which bother to fsck would want to stop the spread
whether they are on HFS+ themselves or not), and hardly
anybody will be affected (because the blocked names are
variants of .git with invisible Unicode code-points mixed
in, meaning mischief is almost certainly what the tree
author had in mind).
Ideally these would be controlled by a separate
"fsck.protectHFS" flag. However, it would be much nicer to
be able to enable/disable _any_ fsck flag individually, and
any scheme we choose should match such a system. Given the
likelihood of anybody using such a path in practice, it is
not unreasonable to wait until such a system materializes.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We complain about ".git" in a tree because it cannot be
loaded into the index or checked out. Since we now also
reject ".GIT" case-insensitively, fsck should notice the
same, so that errors do not propagate.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we detect an invalid tag-name header in a tag object,
like, "tag foo bar\n", we feed the pointer starting at "foo
bar" to a printf "%s" formatter. This shows the name, as we
want, but then it keeps printing the rest of the tag buffer,
rather than stopping at the end of the line.
Our tests did not notice because they look only for the
matching line, but the bug is that we print much more than
we wanted to. So we also adjust the test to be more exact.
Note that when fscking tags with "index-pack --strict", this
is even worse. index-pack does not add a trailing
NUL-terminator after the object, so we may actually read
past the buffer and print uninitialized memory. Running
t5302 with valgrind does notice the bug for that reason.
Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We inspect commit objects pretty much in detail in git-fsck, but we just
glanced over the tag objects. Let's be stricter.
Since we do not want to limit 'tag' lines unduly, values that would fail
the refname check only result in warnings, not errors.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
So far, we assumed that the buffer is NUL terminated, but this is not
a safe assumption, now that we opened the fsck_object() API to pass a
buffer directly.
So let's make sure that there is at least an empty line in the buffer.
That way, our checks would fail if the empty line was encountered
prematurely, and consequently we can get away with the current string
comparisons even with non-NUL-terminated buffers are passed to
fsck_object().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fsck'ing an incoming pack, we need to fsck objects that cannot be
read via read_sha1_file() because they are not local yet (and might even
be rejected if transfer.fsckobjects is set to 'true').
For commits, there is a hack in place: we basically cache commit
objects' buffers anyway, but the same is not true, say, for tag objects.
By refactoring fsck_object() to take the object buffer and size as
optional arguments -- optional, because we still fall back to the
previous method to look at the cached commit objects if the caller
passes NULL -- we prepare the machinery for the upcoming handling of tag
objects.
The assumption that such buffers are inherently NUL terminated is now
wrong, of course, hence we pass the size of the buffer so that we can
add a sanity check later, to prevent running past the end of the buffer.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsck_commit_buffer() checks that the number of items in the parents
list of a commit matches the number of parent lines in its buffer or --
if a graft is used -- the number of parents in that graft. Simplify
the code by using commit_list_count() instead of counting by hand.
Also use different variables for the number of lines and the number of
list items, making it easier to compare them.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/skip-prefix:
http-push: refactor parsing of remote object names
imap-send: use skip_prefix instead of using magic numbers
use skip_prefix to avoid repeated calculations
git: avoid magic number with skip_prefix
fetch-pack: refactor parsing in get_ack
fast-import: refactor parsing of spaces
stat_opt: check extra strlen call
daemon: use skip_prefix to avoid magic numbers
fast-import: use skip_prefix for parsing input
use skip_prefix to avoid repeating strings
use skip_prefix to avoid magic numbers
transport-helper: avoid reading past end-of-string
fast-import: fix read of uninitialized argv memory
apply: use skip_prefix instead of raw addition
refactor skip_prefix to return a boolean
avoid using skip_prefix as a boolean
daemon: mark some strings as const
parse_diff_color_slot: drop ofs parameter
The skip_prefix() function returns a pointer to the content
past the prefix, or NULL if the prefix was not found. While
this is nice and simple, in practice it makes it hard to use
for two reasons:
1. When you want to conditionally skip or keep the string
as-is, you have to introduce a temporary variable.
For example:
tmp = skip_prefix(buf, "foo");
if (tmp)
buf = tmp;
2. It is verbose to check the outcome in a conditional, as
you need extra parentheses to silence compiler
warnings. For example:
if ((cp = skip_prefix(buf, "foo"))
/* do something with cp */
Both of these make it harder to use for long if-chains, and
we tend to use starts_with() instead. However, the first line
of "do something" is often to then skip forward in buf past
the prefix, either using a magic constant or with an extra
strlen(3) (which is generally computed at compile time, but
means we are repeating ourselves).
This patch refactors skip_prefix() to return a simple boolean,
and to provide the pointer value as an out-parameter. If the
prefix is not found, the out-parameter is untouched. This
lets you write:
if (skip_prefix(arg, "foo ", &arg))
do_foo(arg);
else if (skip_prefix(arg, "bar ", &arg))
do_bar(arg);
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most callsites which use the commit buffer try to use the
cached version attached to the commit, rather than
re-reading from disk. Unfortunately, that interface provides
only a pointer to the NUL-terminated buffer, with no
indication of the original length.
For the most part, this doesn't matter. People do not put
NULs in their commit messages, and the log code is happy to
treat it all as a NUL-terminated string. However, some code
paths do care. For example, when checking signatures, we
want to be very careful that we verify all the bytes to
avoid malicious trickery.
This patch just adds an optional "size" out-pointer to
get_commit_buffer and friends. The existing callers all pass
NULL (there did not seem to be any obvious sites where we
could avoid an immediate strlen() call, though perhaps with
some further refactoring we could).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each of these sites assumes that commit->buffer is valid.
Since they would segfault if this was not the case, they are
likely to be correct in practice. However, we can
future-proof them by using get_commit_buffer.
And as a side effect, we abstract away the final bare uses
of commit->buffer.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsck_tree() has two different ways to set a flag variable, either by
using a if-statement that guards an assignment, or by using a
bitwise-or assignment operator. Most are done with the former, and
only one variable is assigned with the latter.
Since all the conditions are short-and-sweet, we can afford to
uniformly use the latter style, which makes the resulting code
shorter and easier to read.
Signed-off-by: Hiroyuki Sano <sh19910711@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsck_commit() uses memcmp() to check if the buffer starts with a
certain prefix, and skips the prefix if it does.
This is exactly what skip_prefix() was designed for.
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since fsck_ident doesn't change the content of **ident, the type of
ident could be const char **.
This change is required to rewrite fsck_commit() to use skip_prefix().
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we check whether a timestamp has overflowed, we check
only against ULONG_MAX, meaning that strtoul has overflowed.
However, we also feed these timestamps to system functions
like gmtime, which expect a time_t. On many systems, time_t
is actually smaller than "unsigned long" (e.g., because it
is signed), and we would overflow when using these
functions. We don't know the actual size or signedness of
time_t, but we can easily check for truncation with a simple
assignment.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we check commit objects, we complain if commit->date is
ULONG_MAX, which is an indication that we saw integer
overflow when parsing it. However, we do not do any check at
all for author lines, which also contain a timestamp.
Let's actually check the timestamps on each ident line
with strtoul. This catches both author and committer lines,
and we can get rid of the now-redundant commit->date check.
Note that like the existing check, we compare only against
ULONG_MAX. Now that we are calling strtoul at the site of
the check, we could be slightly more careful and also check
that errno is set to ERANGE. However, this will make further
refactoring in future patches a little harder, and it
doesn't really matter in practice.
For 32-bit systems, one would have to create a commit at the
exact wrong second in 2038. But by the time we get close to
that, all systems will hopefully have moved to 64-bit (and
if they haven't, they have a real problem one second later).
For 64-bit systems, by the time we get close to ULONG_MAX,
all systems will hopefully have been consumed in the fiery
wrath of our expanding Sun.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Having a ".git" entry inside a tree can cause confusing
results on checkout. At the top-level, you could not
checkout such a tree, as it would complain about overwriting
the real ".git" directory. In a subdirectory, you might
check it out, but performing operations in the subdirectory
would confusingly consider the in-tree ".git" directory as
the repository.
The regular git tools already make it hard to accidentally
add such an entry to a tree, and do not allow such entries
to enter the index at all. Teaching fsck about it provides
an additional safety check, and let's us avoid propagating
any such bogosity when transfer.fsckObjects is on.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A tree with meta-paths like '.' or '..' does not work well
with git; the index will refuse to load it or check it out
to the filesystem (and even if we did not have that safety,
it would look like we were overwriting an untracked
directory). For the same reason, it is difficult to create
such a tree with regular git.
Let's warn about these dubious entries during fsck, just in
case somebody has created a bogus tree (and this also lets
us prevent them from propagating when transfer.fsckObjects
is set).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff" had a confusion between taking data from a path in the
working tree and taking data from an object that happens to have
name 0{40} recorded in a tree.
* jk/maint-null-in-trees:
fsck: detect null sha1 in tree entries
do not write null sha1s to on-disk index
diff: do not use null sha1 as a sentinel value
Short of somebody happening to beat the 1 in 2^160 odds of
actually generating content that hashes to the null sha1, we
should never see this value in a tree entry. So let's have
fsck warn if it it seen.
As in the previous commit, we test both blob and submodule
entries to future-proof the test suite against the
implementation depending on connectivity to notice the
error.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The error handling routines add a newline. Remove
the duplicate ones in error messages.
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsck allows a name with > character in it like "name> <email>". Also for
"name email>" fsck says "missing space before email".
More precisely, it seeks for a first '<', checks that ' ' preceeds it.
Then seeks to '<' or '>' and checks that it is the '>'. Missing space is
reported if either '<' is not found or it's not preceeded with ' '.
Change it to following. Seek to '<' or '>', check that it is '<' and is
preceeded with ' '. Seek to '<' or '>' and check that it is '>'. So now
"name> <email>" is rejected as "bad name". More strict name check is the
only change in what is accepted.
Report 'missing space' only if '<' is found and is not preceeded with a
space.
Signed-off-by: Dmitry Ivankov <divanorama@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jm/maint-misc-fix:
read_gitfile_gently: use ssize_t to hold read result
remove tests of always-false condition
rerere.c: diagnose a corrupt MERGE_RR when hitting EOF between TAB and '\0'
* fsck.c (fsck_error_function): Don't test obj->sha1 == 0.
It can never be true, since that sha1 member is an array.
* transport.c (set_upstreams): Likewise for ref->new_sha1.
Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a variable-args function, the code for writing into a strbuf is
non-trivial. We ended up cutting and pasting it in several places
because there was no vprintf-style function for strbufs (which in turn
was held up by a lack of va_copy).
Now that we have a fallback va_copy, we can add strbuf_vaddf, the
strbuf equivalent of vsprintf. And we can clean up the cut and paste
mess.
Signed-off-by: Jeff King <peff@peff.net>
Improved-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
daae1922 (fsck: check ident lines in commit objects, 2010-04-24)
taught fsck to expect commit objects to have the form
tree <object name>
<parents>
author <valid ident string>
committer <valid ident string>
log message
The check is overly strict: for example, it errors out with the
message “expected blank line” for perfectly valid commits with an
"encoding ISO-8859-1" line.
Later it might make sense to teach fsck about the rest of the header
and warn about unrecognized header lines, but for simplicity, let’s
accept arbitrary trailing lines for now.
Reported-by: Tuncer Ayaz <tuncer.ayaz@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Check that email addresses do not contain <, >, or newline so they can
be quickly scanned without trouble. The copy() function in ident.c
already ensures that ordinary git commands will not write email
addresses without this property.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is common practice to use the Unix epoch as a fallback date
when a suitable date is not available. This is true of git svn
and possibly other importing tools that import non-git history
into git.
Instead of clobbering established strtoul() error reporting
semantics with our own, preserve the strtoul() error value
of ULONG_MAX for fsck.c to handle.
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These variables were unused and can be removed safely:
builtin-clone.c::cmd_clone(): use_local_hardlinks, use_separate_remote
builtin-fetch-pack.c::find_common(): len
builtin-remote.c::mv(): symref
diff.c::show_stats():show_stats(): total
diffcore-break.c::should_break(): base_size
fast-import.c::validate_raw_date(): date, sign
fsck.c::fsck_tree(): o_sha1, sha1
xdiff-interface.c::parse_num(): read_some
Signed-off-by: Benjamin Kramer <benny.kra@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint:
Fix non-literal format in printf-style calls
git-submodule: Avoid printing a spurious message.
git ls-remote: make usage string match manpage
Makefile: help people who run 'make check' by mistake
These were found using gcc 4.3.2-1ubuntu11 with the warning:
warning: format not a string literal and no format arguments
Incorporated suggestions from Brandon Casey <casey@nrlssc.navy.mil>.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many call sites use strbuf_init(&foo, 0) to initialize local
strbuf variable "foo" which has not been accessed since its
declaration. These can be replaced with a static initialization
using the STRBUF_INIT macro which is just as readable, saves a
function call, and takes up fewer lines.
Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
ba002f3 (builtin-fsck: move common object checking code to fsck.c) did
more than what it claimed to. Most notably, it wrongly made an empty tree
object an error by pretending to only move code from fsck_tree() in
builtin-fsck.c to fsck_tree() in fsck.c, but in fact adding a bogus check
to barf on an empty tree.
An empty tree object is _unusual_. Recent porcelains try reasonably hard
not to let the user create a commit that contains such a tree. Perhaps
warning about them in git-fsck may have some merit.
HOWEVER.
Being unusual and being errorneous are two quite different things. This
is especially true now we seem to use the same fsck_$object() code in
places other than git-fsck itself. For example, receive-pack should not
reject unusual objects, even if it would be a good idea to tighten it to
reject incorrect ones.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The requirements are:
* it may not crash on NULL pointers
* a callback function is needed, as index-pack/unpack-objects
need to do different things
* the type information is needed to check the expected <-> real type
and print better error messages
Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The earlier change df391b192 to rename fsck-objects to fsck broke
fsck-objects. This should fix it again.
Signed-off-by: Mark Wooding <mdw@distorted.org.uk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
