From: Ronnie Sahlberg <sahlberg@xxxxxxxxxx>
Date: Wed, 3 Sep 2014 11:45:43 -0700
We currently do not handle badly named refs well:
$ cp .git/refs/heads/master .git/refs/heads/master.....@\*@\\.
$ git branch
fatal: Reference has invalid format: 'refs/heads/master.....@*@\.'
$ git branch -D master.....@\*@\\.
error: branch 'master.....@*@\.' not found.
Users cannot recover from a badly named ref without manually finding
and deleting the loose ref file or appropriate line in packed-refs.
Making that easier will make it easier to tweak the ref naming rules
in the future, for example to forbid shell metacharacters like '`'
and '"', without putting people in a state that is hard to get out of.
So allow "branch --list" to show these refs and allow "branch -d/-D"
and "update-ref -d" to delete them. Other commands (for example to
rename refs) will continue to not handle these refs but can be changed
in later patches.
Details:
In resolving functions, refuse to resolve refs that don't pass the
git-check-ref-format(1) check unless the new RESOLVE_REF_ALLOW_BAD_NAME
flag is passed. Even with RESOLVE_REF_ALLOW_BAD_NAME, refuse to
resolve refs that escape the refs/ directory and do not match the
pattern [A-Z_]* (think "HEAD" and "MERGE_HEAD").
In locking functions, refuse to act on badly named refs unless they
are being deleted and either are in the refs/ directory or match [A-Z_]*.
Just like other invalid refs, flag resolved, badly named refs with the
REF_ISBROKEN flag, treat them as resolving to null_sha1, and skip them
in all iteration functions except for for_each_rawref.
Flag badly named refs (but not symrefs pointing to badly named refs)
with a REF_BAD_NAME flag to make it easier for future callers to
notice and handle them specially. For example, in a later patch
for-each-ref will use this flag to detect refs whose names can confuse
callers parsing for-each-ref output.
In the transaction API, refuse to create or update badly named refs,
but allow deleting them (unless they try to escape refs/ and don't match
[A-Z_]*).
Signed-off-by: Ronnie Sahlberg <sahlberg@xxxxxxxxxx>
Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
---
builtin/branch.c | 9 +--
cache.h | 17 +++++-
refs.c | 148 ++++++++++++++++++++++++++++++++++++++----------
refs.h | 12 +++-
t/t1430-bad-ref-name.sh | 125 +++++++++++++++++++++++++++++++++++++++-
5 files changed, 273 insertions(+), 38 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index 0c7aac0..7e113d6 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -238,7 +238,8 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
name = mkpathdup(fmt, bname.buf);
target = resolve_ref_unsafe(name,
RESOLVE_REF_READING
- | RESOLVE_REF_NO_RECURSE,
+ | RESOLVE_REF_NO_RECURSE
+ | RESOLVE_REF_ALLOW_BAD_NAME,
sha1, &flags);
if (!target) {
error(remote_branch
@@ -248,7 +249,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
continue;
}
- if (!(flags & REF_ISSYMREF) &&
+ if (!(flags & (REF_ISSYMREF|REF_ISBROKEN)) &&
check_branch_commit(bname.buf, name, sha1, head_rev, kinds,
force)) {
ret = 1;
@@ -268,8 +269,8 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
? _("Deleted remote branch %s (was %s).\n")
: _("Deleted branch %s (was %s).\n"),
bname.buf,
- (flags & REF_ISSYMREF)
- ? target
+ (flags & REF_ISBROKEN) ? "broken"
+ : (flags & REF_ISSYMREF) ? target
: find_unique_abbrev(sha1, DEFAULT_ABBREV));
}
delete_branch_config(bname.buf);
diff --git a/cache.h b/cache.h
index b735f3f..0501f7d 100644
--- a/cache.h
+++ b/cache.h
@@ -981,16 +981,29 @@ extern int read_ref(const char *refname, unsigned char *sha1);
* If flags is non-NULL, set the value that it points to the
* combination of REF_ISPACKED (if the reference was found among the
* packed references), REF_ISSYMREF (if the initial reference was a
- * symbolic reference) and REF_ISBROKEN (if the ref is malformed).
+ * symbolic reference), REF_BAD_NAME (if the reference name is ill
+ * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
+ * (if the ref is malformed or has a bad name). See refs.h for more detail
+ * on each flag.
*
* If ref is not a properly-formatted, normalized reference, return
* NULL. If more than MAXDEPTH recursive symbolic lookups are needed,
* give up and return NULL.
*
- * errno is set to something meaningful on error.
+ * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
+ * name is invalid according to git-check-ref-format(1). If the name
+ * is bad then the value stored in sha1 will be null_sha1 and the two
+ * flags REF_ISBROKEN and REF_BAD_NAME will be set.
+ *
+ * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
+ * directory and do not consist of all caps and underscores cannot be
+ * resolved. The function returns NULL for such ref names.
+ * Caps and underscores refers to the special refs, such as HEAD,
+ * FETCH_HEAD and friends, that all live outside of the refs/ directory.
*/
#define RESOLVE_REF_READING 0x01
#define RESOLVE_REF_NO_RECURSE 0x02
+#define RESOLVE_REF_ALLOW_BAD_NAME 0x04
extern const char *resolve_ref_unsafe(const char *ref, int resolve_flags, unsigned char *sha1, int *flags);
extern char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags);
diff --git a/refs.c b/refs.c
index fe1352a..e7000f2 100644
--- a/refs.c
+++ b/refs.c
@@ -187,8 +187,8 @@ struct ref_dir {
/*
* Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
- * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
- * refs.h.
+ * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
+ * public values; see refs.h.
*/
/*
@@ -196,16 +196,16 @@ struct ref_dir {
* the correct peeled value for the reference, which might be
* null_sha1 if the reference is not a tag or if it is broken.
*/
-#define REF_KNOWS_PEELED 0x08
+#define REF_KNOWS_PEELED 0x10
/* ref_entry represents a directory of references */
-#define REF_DIR 0x10
+#define REF_DIR 0x20
/*
* Entry has not yet been read from disk (used only for REF_DIR
* entries representing loose references)
*/
-#define REF_INCOMPLETE 0x20
+#define REF_INCOMPLETE 0x40
/*
* A ref_entry represents either a reference or a "subdirectory" of
@@ -274,6 +274,39 @@ static struct ref_dir *get_ref_dir(struct ref_entry *entry)
return dir;
}
+/*
+ * Check if a refname is safe.
+ * For refs that start with "refs/" we consider it safe as long they do
+ * not try to resolve to outside of refs/.
+ *
+ * For all other refs we only consider them safe iff they only contain
+ * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like
+ * "config").
+ */
+static int refname_is_safe(const char *refname)
+{
+ if (starts_with(refname, "refs/")) {
+ char *buf;
+ int result;
+
+ buf = xmalloc(strlen(refname) + 1);
+ /*
+ * Does the refname try to escape refs/?
+ * For example: refs/foo/../bar is safe but refs/foo/../../bar
+ * is not.
+ */
+ result = !normalize_path_copy(buf, refname + strlen("refs/"));
+ free(buf);
+ return result;
+ }
+ while (*refname) {
+ if (!isupper(*refname) && *refname != '_')
+ return 0;
+ refname++;
+ }
+ return 1;
+}
+
static struct ref_entry *create_ref_entry(const char *refname,
const unsigned char *sha1, int flag,
int check_name)
@@ -284,6 +317,8 @@ static struct ref_entry *create_ref_entry(const char *refname,
if (check_name &&
check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
die("Reference has invalid format: '%s'", refname);
+ if (!check_name && !refname_is_safe(refname))
+ die("Reference has invalid name: '%s'", refname);
len = strlen(refname) + 1;
ref = xmalloc(sizeof(struct ref_entry) + len);
hashcpy(ref->u.value.sha1, sha1);
@@ -1111,7 +1146,13 @@ static void read_packed_refs(FILE *f, struct ref_dir *dir)
refname = parse_ref_line(refline, sha1);
if (refname) {
- last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
+ int flag = REF_ISPACKED;
+
+ if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+ hashclr(sha1);
+ flag |= REF_BAD_NAME | REF_ISBROKEN;
+ }
+ last = create_ref_entry(refname, sha1, flag, 0);
if (peeled == PEELED_FULLY ||
(peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
last->flag |= REF_KNOWS_PEELED;
@@ -1249,8 +1290,13 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir)
hashclr(sha1);
flag |= REF_ISBROKEN;
}
+ if (check_refname_format(refname.buf,
+ REFNAME_ALLOW_ONELEVEL)) {
+ hashclr(sha1);
+ flag |= REF_BAD_NAME | REF_ISBROKEN;
+ }
add_entry_to_dir(dir,
- create_ref_entry(refname.buf, sha1, flag, 1));
+ create_ref_entry(refname.buf, sha1, flag, 0));
}
strbuf_setlen(&refname, dirnamelen);
}
@@ -1369,10 +1415,10 @@ static struct ref_entry *get_packed_ref(const char *refname)
* A loose ref file doesn't exist; check for a packed ref. The
* options are forwarded from resolve_safe_unsafe().
*/
-static const char *handle_missing_loose_ref(const char *refname,
- int resolve_flags,
- unsigned char *sha1,
- int *flags)
+static int resolve_missing_loose_ref(const char *refname,
+ int resolve_flags,
+ unsigned char *sha1,
+ int *flags)
{
struct ref_entry *entry;
@@ -1385,14 +1431,15 @@ static const char *handle_missing_loose_ref(const char *refname,
hashcpy(sha1, entry->u.value.sha1);
if (flags)
*flags |= REF_ISPACKED;
- return refname;
+ return 0;
}
/* The reference is not a packed reference, either. */
if (resolve_flags & RESOLVE_REF_READING) {
- return NULL;
+ errno = ENOENT;
+ return -1;
} else {
hashclr(sha1);
- return refname;
+ return 0;
}
}
@@ -1403,13 +1450,29 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
ssize_t len;
char buffer[256];
static char refname_buffer[256];
+ int bad_name = 0;
if (flags)
*flags = 0;
if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
- errno = EINVAL;
- return NULL;
+ if (flags)
+ *flags |= REF_BAD_NAME;
+
+ if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+ !refname_is_safe(refname)) {
+ errno = EINVAL;
+ return NULL;
+ }
+ /*
+ * dwim_ref() uses REF_ISBROKEN to distinguish between
+ * missing refs and refs that were present but invalid,
+ * to complain about the latter to stderr.
+ *
+ * We don't know whether the ref exists, so don't set
+ * REF_ISBROKEN yet.
+ */
+ bad_name = 1;
}
for (;;) {
char path[PATH_MAX];
@@ -1435,11 +1498,17 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
*/
stat_ref:
if (lstat(path, &st) < 0) {
- if (errno == ENOENT)
- return handle_missing_loose_ref(refname,
- resolve_flags, sha1, flags);
- else
+ if (errno != ENOENT)
return NULL;
+ if (resolve_missing_loose_ref(refname, resolve_flags,
+ sha1, flags))
+ return NULL;
+ if (bad_name) {
+ hashclr(sha1);
+ if (flags)
+ *flags |= REF_ISBROKEN;
+ }
+ return refname;
}
/* Follow "normalized" - ie "refs/.." symlinks by hand */
@@ -1512,6 +1581,11 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
errno = EINVAL;
return NULL;
}
+ if (bad_name) {
+ hashclr(sha1);
+ if (flags)
+ *flags |= REF_ISBROKEN;
+ }
return refname;
}
if (flags)
@@ -1527,8 +1601,13 @@ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned
if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
if (flags)
*flags |= REF_ISBROKEN;
- errno = EINVAL;
- return NULL;
+
+ if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+ !refname_is_safe(buf)) {
+ errno = EINVAL;
+ return NULL;
+ }
+ bad_name = 1;
}
}
}
@@ -2160,18 +2239,16 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname,
int missing = 0;
int attempts_remaining = 3;
- if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
- errno = EINVAL;
- return NULL;
- }
-
lock = xcalloc(1, sizeof(struct ref_lock));
lock->lock_fd = -1;
if (mustexist)
resolve_flags |= RESOLVE_REF_READING;
- if (flags & REF_NODEREF && flags & REF_DELETING)
- resolve_flags |= RESOLVE_REF_NO_RECURSE;
+ if (flags & REF_DELETING) {
+ resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
+ if (flags & REF_NODEREF)
+ resolve_flags |= RESOLVE_REF_NO_RECURSE;
+ }
refname = resolve_ref_unsafe(refname, resolve_flags,
lock->old_sha1, &type);
@@ -3519,6 +3596,13 @@ int ref_transaction_update(struct ref_transaction *transaction,
if (have_old && !old_sha1)
die("BUG: have_old is true but old_sha1 is NULL");
+ if (!is_null_sha1(new_sha1) &&
+ check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+ strbuf_addf(err, "refusing to update ref with bad name %s",
+ refname);
+ return -1;
+ }
+
update = add_update(transaction, refname);
hashcpy(update->new_sha1, new_sha1);
update->flags = flags;
@@ -3544,6 +3628,12 @@ int ref_transaction_create(struct ref_transaction *transaction,
if (!new_sha1 || is_null_sha1(new_sha1))
die("BUG: create ref with null new_sha1");
+ if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+ strbuf_addf(err, "refusing to create ref with bad name %s",
+ refname);
+ return -1;
+ }
+
update = add_update(transaction, refname);
hashcpy(update->new_sha1, new_sha1);
diff --git a/refs.h b/refs.h
index c61b8f4..2bc3556 100644
--- a/refs.h
+++ b/refs.h
@@ -56,12 +56,20 @@ struct ref_transaction;
/*
* Reference cannot be resolved to an object name: dangling symbolic
- * reference (directly or indirectly), corrupt reference file, or
- * symbolic reference refers to ill-formatted reference name.
+ * reference (directly or indirectly), corrupt reference file,
+ * reference exists but name is bad, or symbolic reference refers to
+ * ill-formatted reference name.
*/
#define REF_ISBROKEN 0x04
/*
+ * Reference name is not well formed.
+ *
+ * See git-check-ref-format(1) for the definition of well formed ref names.
+ */
+#define REF_BAD_NAME 0x08
+
+/*
* The signature for the callback function for the for_each_*()
* functions below. The memory pointed to by the refname and sha1
* arguments is only guaranteed to be valid for the duration of a
diff --git a/t/t1430-bad-ref-name.sh b/t/t1430-bad-ref-name.sh
index c7b19b0..468e856 100755
--- a/t/t1430-bad-ref-name.sh
+++ b/t/t1430-bad-ref-name.sh
@@ -4,7 +4,8 @@ test_description='Test handling of ref names that check-ref-format rejects'
. ./test-lib.sh
test_expect_success setup '
- test_commit one
+ test_commit one &&
+ test_commit two
'
test_expect_success 'fast-import: fail on invalid branch name ".badbranchname"' '
@@ -37,6 +38,107 @@ test_expect_success 'fast-import: fail on invalid branch name "bad[branch]name"'
test_must_fail git fast-import <input
'
+test_expect_success 'git branch shows badly named ref' '
+ cp .git/refs/heads/master .git/refs/heads/broken...ref &&
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ git branch >output &&
+ grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'branch -d can delete badly named ref' '
+ cp .git/refs/heads/master .git/refs/heads/broken...ref &&
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ git branch -d broken...ref &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'branch -D can delete badly named ref' '
+ cp .git/refs/heads/master .git/refs/heads/broken...ref &&
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ git branch -D broken...ref &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'branch -D cannot delete non-ref in .git dir' '
+ echo precious >.git/my-private-file &&
+ echo precious >expect &&
+ test_must_fail git branch -D ../../my-private-file &&
+ test_cmp expect .git/my-private-file
+'
+
+test_expect_success 'branch -D cannot delete absolute path' '
+ git branch -f extra &&
+ test_must_fail git branch -D "$(pwd)/.git/refs/heads/extra" &&
+ test_cmp_rev HEAD extra
+'
+
+test_expect_success 'git branch cannot create a badly named ref' '
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ test_must_fail git branch broken...ref &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'branch -m cannot rename to a bad ref name' '
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ test_might_fail git branch -D goodref &&
+ git branch goodref &&
+ test_must_fail git branch -m goodref broken...ref &&
+ test_cmp_rev master goodref &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_failure 'branch -m can rename from a bad ref name' '
+ cp .git/refs/heads/master .git/refs/heads/broken...ref &&
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ git branch -m broken...ref renamed &&
+ test_cmp_rev master renamed &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'push cannot create a badly named ref' '
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ test_must_fail git push "file://$(pwd)" HEAD:refs/heads/broken...ref &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_failure 'push --mirror can delete badly named ref' '
+ top=$(pwd) &&
+ git init src &&
+ git init dest &&
+
+ (
+ cd src &&
+ test_commit one
+ ) &&
+ (
+ cd dest &&
+ test_commit two &&
+ git checkout --detach &&
+ cp .git/refs/heads/master .git/refs/heads/broken...ref
+ ) &&
+ git -C src push --mirror "file://$top/dest" &&
+ git -C dest branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'rev-parse skips symref pointing to broken name' '
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ git branch shadow one &&
+ cp .git/refs/heads/master .git/refs/heads/broken...ref &&
+ git symbolic-ref refs/tags/shadow refs/heads/broken...ref &&
+
+ git rev-parse --verify one >expect &&
+ git rev-parse --verify shadow >actual 2>err &&
+ test_cmp expect actual &&
+ test_i18ngrep "ignoring.*refs/tags/shadow" err
+'
+
test_expect_success 'update-ref --no-deref -d can delete reference to broken name' '
git symbolic-ref refs/heads/badname refs/heads/broken...ref &&
test_when_finished "rm -f .git/refs/heads/badname" &&
@@ -45,6 +147,27 @@ test_expect_success 'update-ref --no-deref -d can delete reference to broken nam
test_path_is_missing .git/refs/heads/badname
'
+test_expect_success 'update-ref -d can delete broken name' '
+ cp .git/refs/heads/master .git/refs/heads/broken...ref &&
+ test_when_finished "rm -f .git/refs/heads/broken...ref" &&
+ git update-ref -d refs/heads/broken...ref &&
+ git branch >output &&
+ ! grep -e "broken\.\.\.ref" output
+'
+
+test_expect_success 'update-ref -d cannot delete non-ref in .git dir' '
+ echo precious >.git/my-private-file &&
+ echo precious >expect &&
+ test_must_fail git update-ref -d my-private-file &&
+ test_cmp expect .git/my-private-file
+'
+
+test_expect_success 'update-ref -d cannot delete absolute path' '
+ git branch -f extra &&
+ test_must_fail git update-ref -d "$(pwd)/.git/refs/heads/extra" &&
+ test_cmp_rev HEAD extra
+'
+
test_expect_success 'update-ref --stdin fails create with bad ref name' '
echo "create ~a refs/heads/master" >stdin &&
test_must_fail git update-ref --stdin <stdin 2>err &&
--
2.1.0.rc2.206.gedb03e5
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