When checking whether a commit was rewritten to a single object id, we
use a glob that insists on a 40-hex result. This works for sha1, but
fails t7003 when run with GIT_TEST_DEFAULT_HASH=sha256.
Since the previous commit simplified the case statement here, we only
have two arms: an empty string or a single object id. We can just loosen
our glob to match anything, and still distinguish those cases (we lose
the ability to notice bogus input, but that's not a problem; we are the
one who wrote the map in the first place, and anyway update-ref will
complain loudly if the input isn't a valid hash).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a ref maps to a commit that is neither rewritten nor kept by
filter-branch (e.g., because it was eliminated by rev-list's pathspec
selection), we rewrite it to its nearest ancestor.
Since the initial commit in 6f6826c52b (Add git-filter-branch,
2007-06-03), we have warned when there are multiple such ancestors in
the map file. However, the warning code is impossible to trigger these
days. Since a0e46390d3 (filter-branch: fix ref rewriting with
--subdirectory-filter, 2008-08-12), we find the ancestor using "rev-list
-1", so it can only ever have a single value.
This code is made doubly confusing by the fact that we append to the map
file when mapping ancestors. However, this can never yield multiple
values because:
- we explicitly check whether the map already exists, and if so, do
nothing (so our "append" will always be to a file that does not
exist)
- even if we were to try mapping twice, the process to do so is
deterministic. I.e., we'd always end up with the same ancestor for a
given sha1. So warning about it would be pointless; there is no
ambiguity.
So swap out the warning code for a BUG (which we'll simplify further in
the next commit). And let's stop using the append operator to make the
ancestor-mapping code less confusing.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After it has rewritten all of the commits, filter-branch will then
rewrite each of the input refs based on the resulting map of old/new
commits. But we don't have any explicit test coverage of this code.
Let's make sure we are covering each of those cases:
- deleting a ref when all of its commits were pruned
- rewriting a ref based on the mapping (this happens throughout the
script, but let's make sure we generate the correct messages)
- rewriting a ref whose tip was excluded, in which case we rewrite to
the nearest ancestor. Note in this case that we still insist that no
"warning" line is present (even though it looks like we'd trigger
the "... was rewritten into multiple commits" one). See the next
commit for more details.
Note these all pass currently, but the latter two will fail when run
with GIT_TEST_DEFAULT_HASH=sha256.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.22:
Git 2.22.5
Git 2.21.4
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.21:
Git 2.21.4
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.20:
Git 2.20.5
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.19:
Git 2.19.6
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.18:
Git 2.18.5
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
* maint-2.17:
Git 2.17.6
unpack_trees(): start with a fresh lstat cache
run-command: invalidate lstat cache after a command finished
checkout: fix bug that makes checkout follow symlinks in leading path
We really want to avoid relying on stale information.
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the previous commit, we intercepted calls to `rmdir()` to invalidate
the lstat cache in the successful case, so that the lstat cache could
not have the idea that a directory exists where there is none.
The same situation can arise, of course, when a separate process is
spawned (most notably, this is the case in `submodule_move_head()`).
Obviously, we cannot know whether a directory was removed in that
process, therefore we must invalidate the lstat cache afterwards.
Note: in contrast to `lstat_cache_aware_rmdir()`, we invalidate the
lstat cache even in case of an error: the process might have removed a
directory and still have failed afterwards.
Co-authored-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Before checking out a file, we have to confirm that all of its leading
components are real existing directories. And to reduce the number of
lstat() calls in this process, we cache the last leading path known to
contain only directories. However, when a path collision occurs (e.g.
when checking out case-sensitive files in case-insensitive file
systems), a cached path might have its file type changed on disk,
leaving the cache on an invalid state. Normally, this doesn't bring
any bad consequences as we usually check out files in index order, and
therefore, by the time the cached path becomes outdated, we no longer
need it anyway (because all files in that directory would have already
been written).
But, there are some users of the checkout machinery that do not always
follow the index order. In particular: checkout-index writes the paths
in the same order that they appear on the CLI (or stdin); and the
delayed checkout feature -- used when a long-running filter process
replies with "status=delayed" -- postpones the checkout of some entries,
thus modifying the checkout order.
When we have to check out an out-of-order entry and the lstat() cache is
invalid (due to a previous path collision), checkout_entry() may end up
using the invalid data and thrusting that the leading components are
real directories when, in reality, they are not. In the best case
scenario, where the directory was replaced by a regular file, the user
will get an error: "fatal: unable to create file 'foo/bar': Not a
directory". But if the directory was replaced by a symlink, checkout
could actually end up following the symlink and writing the file at a
wrong place, even outside the repository. Since delayed checkout is
affected by this bug, it could be used by an attacker to write
arbitrary files during the clone of a maliciously crafted repository.
Some candidate solutions considered were to disable the lstat() cache
during unordered checkouts or sort the entries before passing them to
the checkout machinery. But both ideas include some performance penalty
and they don't future-proof the code against new unordered use cases.
Instead, we now manually reset the lstat cache whenever we successfully
remove a directory. Note: We are not even checking whether the directory
was the same as the lstat cache points to because we might face a
scenario where the paths refer to the same location but differ due to
case folding, precomposed UTF-8 issues, or the presence of `..`
components in the path. Two regression tests, with case-collisions and
utf8-collisions, are also added for both checkout-index and delayed
checkout.
Note: to make the previously mentioned clone attack unfeasible, it would
be sufficient to reset the lstat cache only after the remove_subtree()
call inside checkout_entry(). This is the place where we would remove a
directory whose path collides with the path of another entry that we are
currently trying to check out (possibly a symlink). However, in the
interest of a thorough fix that does not leave Git open to
similar-but-not-identical attack vectors, we decided to intercept
all `rmdir()` calls in one fell swoop.
This addresses CVE-2021-21300.
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
GitHub Actions is transitioning workflow steps that run on
'ubuntu-latest' from 18.04 to 20.04 [1].
This works fine in all steps except the static-analysis one, since
Coccinelle isn't available on Ubuntu focal (it is only available in the
universe suite).
Until Coccinelle can be installed from 20.04's main suite, pin the
static-analysis build to run on 18.04, where it can be installed by
default.
[1]: https://github.com/actions/virtual-environments/issues/1816
Reported-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our setting of GitHub CI test jobs were a bit too eager to give up
once there is even one failure found. Tweak the knob to allow
other jobs keep running even when we see a failure, so that we can
find more failures in a single run.
* pb/ci-matrix-wo-shortcut:
ci: do not cancel all jobs of a matrix if one fails
The implementation of "git branch --sort" wrt the detached HEAD
display has always been hacky, which has been cleaned up.
* ab/branch-sort:
branch: show "HEAD detached" first under reverse sort
branch: sort detached HEAD based on a flag
ref-filter: move ref_sorting flags to a bitfield
ref-filter: move "cmp_fn" assignment into "else if" arm
ref-filter: add braces to if/else if/else chain
branch tests: add to --sort tests
branch: change "--local" to "--list" in comment
Code clean-up.
* ma/t1300-cleanup:
t1300: don't needlessly work with `core.foo` configs
t1300: remove duplicate test for `--file no-such-file`
t1300: remove duplicate test for `--file ../foo`
A 3-year old test that was not testing anything useful has been
corrected.
* fc/t6030-bisect-reset-removes-auxiliary-files:
test: bisect-porcelain: fix location of files
Jeff King
Johannes Schindelin
Matheus Tavares
Junio C Hamano
Taylor Blau