From: Kevin Locke <kevin@kevinlocke.name>
To: git@vger.kernel.org
Cc: Elijah Newren <newren@gmail.com>,
Junio C Hamano <gitster@pobox.com>,
Derrick Stolee <derrickstolee@github.com>
Subject: [PATCH v4] setup: don't die if realpath(3) fails on getcwd(3)
Date: Tue, 24 May 2022 13:20:12 -0600 [thread overview]
Message-ID: <8b20840014d214023c50ee62439147f798e6f9cc.1653419993.git.kevin@kevinlocke.name> (raw)
In-Reply-To: <68c66aef7ca4dba53faec9e6d2f3b70fe58ac33e.1653403877.git.kevin@kevinlocke.name>
Prior to Git 2.35.0, git could be run from an inaccessible working
directory so long as the git repository specified by options and/or
environment variables was accessible. For example:
git init repo
mkdir -p a/b
cd a/b
chmod u-x ..
git -C "${PWD%/a/b}/repo" status
If this example seems a bit contrived, consider running with the
repository owner as a substitute UID (e.g. with runuser(1) or sudo(8))
without ensuring the working directory is accessible by that user.
The code added by e6f8861bd4 ("setup: introduce
startup_info->original_cwd") to preserve the working directory attempts
to normalize the path using strbuf_realpath(). If that fails, as in the
case above, it is treated as a fatal error.
This commit treats strbuf_realpath() errors as non-fatal. If an error
occurs, setup_original_cwd() will continue without applying removal
prevention for cwd, resulting in the pre-2.35.0 behavior. The risk
should be minimal, since git will not operate on a repository with
inaccessible ancestors, this behavior is only known to occur when cwd is
a descendant of the repository, an ancestor of cwd is inaccessible, and
no ancestors of the repository are inaccessible.
Signed-off-by: Kevin Locke <kevin@kevinlocke.name>
---
Changes since v3:
* Free tmp_original_cwd in both codepaths.
* Return after strbuf_realpath() fails, rather than jumping to
no_prevention_needed, to avoid unnecessary free(NULL) and NULL
reassignment.
* Invert the condition and remove the else block to match the
return-on-error code style for better readability.
* Stop adding "Try" to comment, since strbuf_realpath() hasn't
been optional since v1.
Changes since v2:
* Use trace2_data_string(), rather than trace_printf(), to report
realpath failure.
Changes since v1:
* Set startup_info->original_cwd = NULL when strbuf_realpath() fails,
rather than setting it to the un-normalized path.
* Add a trace message when realpath fails to aid debugging.
* Remove potential realpath failure cause from comment before it.
* Improve format for reference to e6f8861bd4 in commit message.
* Clarify when the pre-2.35.0 behavior may occur as a result of this
commit in the commit message.
* Remove 'Fixes:' tag from commit message.
setup.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/setup.c b/setup.c
index a7b36f3ffbf..e0a99df512f 100644
--- a/setup.c
+++ b/setup.c
@@ -459,7 +459,16 @@ static void setup_original_cwd(void)
*/
/* Normalize the directory */
- strbuf_realpath(&tmp, tmp_original_cwd, 1);
+ if (!strbuf_realpath(&tmp, tmp_original_cwd, 0)) {
+ trace2_data_string("setup", the_repository,
+ "realpath-path", tmp_original_cwd);
+ trace2_data_string("setup", the_repository,
+ "realpath-failure", strerror(errno));
+ free((char*)tmp_original_cwd);
+ tmp_original_cwd = NULL;
+ return;
+ }
+
free((char*)tmp_original_cwd);
tmp_original_cwd = NULL;
startup_info->original_cwd = strbuf_detach(&tmp, NULL);
--
2.35.1
next prev parent reply other threads:[~2022-05-24 19:20 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-19 23:39 [PATCH] setup: don't die if realpath(3) fails on getcwd(3) Kevin Locke
2022-05-20 18:38 ` Junio C Hamano
2022-05-21 0:14 ` Elijah Newren
2022-05-21 13:02 ` Kevin Locke
2022-05-23 18:44 ` Derrick Stolee
2022-05-21 13:53 ` [PATCH v2] " Kevin Locke
2022-05-23 18:57 ` Derrick Stolee
2022-05-24 14:02 ` Kevin Locke
2022-05-24 15:20 ` Elijah Newren
2022-05-24 17:38 ` Derrick Stolee
2022-05-25 3:47 ` Elijah Newren
2022-05-27 7:48 ` Ævar Arnfjörð Bjarmason
2022-05-28 1:27 ` Elijah Newren
2022-05-24 14:51 ` [PATCH v3] " Kevin Locke
2022-05-24 15:21 ` Elijah Newren
2022-05-24 17:41 ` Derrick Stolee
2022-05-24 18:00 ` Kevin Locke
2022-05-24 19:20 ` Kevin Locke [this message]
2022-05-24 20:40 ` [PATCH v4] " Derrick Stolee
2022-05-24 21:25 ` Junio C Hamano
2022-05-25 3:51 ` Elijah Newren
2022-05-25 5:11 ` Junio C Hamano
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