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Revert "chase: invert CHASE_NO_AUTOFS and only set it where needed"

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This reverts commit 490aa05ca1.

As commented https://github.com/systemd/systemd/pull/38569#discussion_r2284978273,
the commit makes autofs check bypassed. Before the commit, when
CHASE_NO_AUTOFS is set, we did not shortcut chasing paths, and refused
any autofs mount points in the path. However, with the commit, the flag
was swapped but even when CHASE_AUTOFS is unset, the autofs check may be
skipped.

To fix the issue, rather than swapping the flag, we should introduce
another flag, say CHASE_TRIGGER_AUTOFS. This revert the commit, and in a
later commit, the new flag will be introduced.
This commit is contained in:
Yu Watanabe
2025-08-20 02:15:36 +09:00
parent 1441f2e992
commit 2e7d7e929e
19 changed files with 59 additions and 75 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/basic/chase.c
+13 -13
View File
@@ -83,7 +83,7 @@ static int openat_opath_with_automount(int dir_fd, const char *path, bool automo
/* Pin an inode via O_PATH semantics. Sounds pretty obvious to do this, right? You just do open()
* with O_PATH, and there you go. But uh, it's not that easy. open() via O_PATH does not trigger
* automounts, but we usually want that (when CHASE_AUTOFS is used). But thankfully there's
* automounts, but we usually want that (except if CHASE_NO_AUTOFS is used). But thankfully there's
* a way out: the newer open_tree() call, when specified without OPEN_TREE_CLONE actually is fully
* equivalent to open() with O_PATH – except for one thing: it triggers automounts.
*
@@ -202,7 +202,7 @@ int chaseat(int dir_fd, const char *path, ChaseFlags flags, char **ret_path, int
* -ENOLINK. If CHASE_WARN is also set, a warning describing the unsafe transition is emitted.
* CHASE_WARN cannot be used in PID 1.
*
* 5. Without CHASE_AUTOFS: in this case if an autofs mount point is encountered, path normalization
* 5. With CHASE_NO_AUTOFS: in this case if an autofs mount point is encountered, path normalization
* is aborted and -EREMOTE is returned. If CHASE_WARN is also set, a warning showing the path of
* the mount point is emitted. CHASE_WARN cannot be used in PID 1.
*/
@@ -219,7 +219,7 @@ int chaseat(int dir_fd, const char *path, ChaseFlags flags, char **ret_path, int
}
if (!(flags &
(CHASE_AT_RESOLVE_IN_ROOT|CHASE_NONEXISTENT|CHASE_AUTOFS|CHASE_SAFE|CHASE_STEP|
(CHASE_AT_RESOLVE_IN_ROOT|CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_STEP|
CHASE_PROHIBIT_SYMLINKS|CHASE_MKDIR_0755|CHASE_PARENT)) &&
!ret_path && ret_fd) {
@@ -396,7 +396,7 @@ int chaseat(int dir_fd, const char *path, ChaseFlags flags, char **ret_path, int
}
/* Otherwise let's pin it by file descriptor, via O_PATH. */
child = r = openat_opath_with_automount(fd, first, /* automount = */ FLAGS_SET(flags, CHASE_AUTOFS));
child = r = openat_opath_with_automount(fd, first, /* automount = */ !FLAGS_SET(flags, CHASE_NO_AUTOFS));
if (r < 0) {
if (r != -ENOENT)
return r;
@@ -435,7 +435,7 @@ int chaseat(int dir_fd, const char *path, ChaseFlags flags, char **ret_path, int
unsafe_transition(&st, &st_child))
return log_unsafe_transition(fd, child, path, flags);
if (!FLAGS_SET(flags, CHASE_AUTOFS) &&
if (FLAGS_SET(flags, CHASE_NO_AUTOFS) &&
fd_is_fs_type(child, AUTOFS_SUPER_MAGIC) > 0)
return log_autofs_mount_point(child, path, flags);
@@ -783,7 +783,7 @@ int chase_and_open(
assert(!(chase_flags & (CHASE_NONEXISTENT|CHASE_STEP)));
if (empty_or_root(root) && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
/* Shortcut this call if none of the special features of this call are requested */
return xopenat_full(AT_FDCWD, path,
open_flags | (FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? O_NOFOLLOW : 0),
@@ -822,7 +822,7 @@ int chase_and_opendir(const char *path, const char *root, ChaseFlags chase_flags
assert(ret_dir);
if (empty_or_root(root) && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0) {
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0) {
/* Shortcut this call if none of the special features of this call are requested */
d = opendir(path);
if (!d)
@@ -858,7 +858,7 @@ int chase_and_stat(const char *path, const char *root, ChaseFlags chase_flags, c
assert(ret_stat);
if (empty_or_root(root) && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
/* Shortcut this call if none of the special features of this call are requested */
return RET_NERRNO(fstatat(AT_FDCWD, path, ret_stat,
FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? AT_SYMLINK_NOFOLLOW : 0));
@@ -886,7 +886,7 @@ int chase_and_access(const char *path, const char *root, ChaseFlags chase_flags,
assert(!(chase_flags & (CHASE_NONEXISTENT|CHASE_STEP)));
if (empty_or_root(root) && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
/* Shortcut this call if none of the special features of this call are requested */
return RET_NERRNO(faccessat(AT_FDCWD, path, access_mode,
FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? AT_SYMLINK_NOFOLLOW : 0));
@@ -992,7 +992,7 @@ int chase_and_openat(
assert(!(chase_flags & (CHASE_NONEXISTENT|CHASE_STEP)));
if (dir_fd == AT_FDCWD && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
/* Shortcut this call if none of the special features of this call are requested */
return xopenat_full(dir_fd, path,
open_flags | (FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? O_NOFOLLOW : 0),
@@ -1029,7 +1029,7 @@ int chase_and_opendirat(int dir_fd, const char *path, ChaseFlags chase_flags, ch
assert(ret_dir);
if (dir_fd == AT_FDCWD && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0) {
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0) {
/* Shortcut this call if none of the special features of this call are requested */
d = opendir(path);
if (!d)
@@ -1065,7 +1065,7 @@ int chase_and_statat(int dir_fd, const char *path, ChaseFlags chase_flags, char
assert(ret_stat);
if (dir_fd == AT_FDCWD && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
/* Shortcut this call if none of the special features of this call are requested */
return RET_NERRNO(fstatat(AT_FDCWD, path, ret_stat,
FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? AT_SYMLINK_NOFOLLOW : 0));
@@ -1093,7 +1093,7 @@ int chase_and_accessat(int dir_fd, const char *path, ChaseFlags chase_flags, int
assert(!(chase_flags & (CHASE_NONEXISTENT|CHASE_STEP)));
if (dir_fd == AT_FDCWD && !ret_path &&
(chase_flags & (CHASE_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
(chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_PROHIBIT_SYMLINKS|CHASE_PARENT|CHASE_MKDIR_0755)) == 0)
/* Shortcut this call if none of the special features of this call are requested */
return RET_NERRNO(faccessat(AT_FDCWD, path, access_mode,
FLAGS_SET(chase_flags, CHASE_NOFOLLOW) ? AT_SYMLINK_NOFOLLOW : 0));
src/basic/chase.h
+1 -1
View File
@@ -6,7 +6,7 @@
typedef enum ChaseFlags {
CHASE_PREFIX_ROOT = 1 << 0, /* The specified path will be prefixed by the specified root before beginning the iteration */
CHASE_NONEXISTENT = 1 << 1, /* It's OK if the path doesn't actually exist. */
CHASE_AUTOFS = 1 << 2, /* Trigger automount if autofs mount point found instead of returning -EREMOTE */
CHASE_NO_AUTOFS = 1 << 2, /* Return -EREMOTE if autofs mount point found */
CHASE_SAFE = 1 << 3, /* Return -EPERM if we ever traverse from unprivileged to privileged files or directories */
CHASE_TRAIL_SLASH = 1 << 4, /* Any trailing slash will be preserved */
CHASE_STEP = 1 << 5, /* Just execute a single step of the normalization */