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tmpfiles: don't follow symlinks when adjusting ACLs, fille attributes, access modes or ownership

This commit is contained in:
Lennart Poettering 2015-04-13 15:16:54 +02:00
parent 0e336347de
commit 48b8aaa827
1 changed files with 81 additions and 41 deletions
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122
src/tmpfiles/tmpfiles.c
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@ -583,51 +583,69 @@ finish:
}
static int path_set_perms(Item *i, const char *path) {
_cleanup_close_ int fd = -1;
struct stat st;
bool st_valid;
assert(i);
assert(path);
st_valid = stat(path, &st) == 0;
/* We open the file with O_PATH here, to make the operation
* somewhat atomic. Also there's unfortunately no fchmodat()
* with AT_SYMLINK_NOFOLLOW, hence we emulate it here via
* O_PATH. */
/* not using i->path directly because it may be a glob */
if (i->mode_set) {
mode_t m = i->mode;
fd = open(path, O_RDONLY|O_NOFOLLOW|O_CLOEXEC|O_PATH|O_NOATIME);
if (fd < 0)
return log_error_errno(errno, "Adjusting owner and mode for %s failed: %m", path);
if (i->mask_perms && st_valid) {
if (!(st.st_mode & 0111))
m &= ~0111;
if (!(st.st_mode & 0222))
if (fstatat(fd, "", &st, AT_EMPTY_PATH) < 0)
return log_error_errno(errno, "Failed to fstat() file %s: %m", path);
if (S_ISLNK(st.st_mode))
log_debug("Skipping mode an owner fix for symlink %s.", path);
else {
char fn[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
xsprintf(fn, "/proc/self/fd/%i", fd);
/* not using i->path directly because it may be a glob */
if (i->mode_set) {
mode_t m = i->mode;
if (i->mask_perms) {
if (!(st.st_mode & 0111))
m &= ~0111;
if (!(st.st_mode & 0222))
m &= ~0222;
if (!(st.st_mode & 0444))
m &= ~0444;
if (!S_ISDIR(st.st_mode))
m &= ~07000; /* remove sticky/sgid/suid bit, unless directory */
if (!(st.st_mode & 0444))
m &= ~0444;
if (!S_ISDIR(st.st_mode))
m &= ~07000; /* remove sticky/sgid/suid bit, unless directory */
}
if (m == (st.st_mode & 07777))
log_debug("\"%s\" has right mode %o", path, st.st_mode);
else {
log_debug("chmod \"%s\" to mode %o", path, m);
if (chmod(fn, m) < 0)
return log_error_errno(errno, "chmod(%s) failed: %m", path);
}
}
if (st_valid && m == (st.st_mode & 07777))
log_debug("\"%s\" has right mode %o", path, st.st_mode);
else {
log_debug("chmod \"%s\" to mode %o", path, m);
if (chmod(path, m) < 0)
return log_error_errno(errno, "chmod(%s) failed: %m", path);
}
}
if ((!st_valid || i->uid != st.st_uid || i->gid != st.st_gid) &&
(i->uid_set || i->gid_set)) {
log_debug("chown \"%s\" to "UID_FMT"."GID_FMT,
path,
i->uid_set ? i->uid : UID_INVALID,
i->gid_set ? i->gid : GID_INVALID);
if (chown(path,
i->uid_set ? i->uid : UID_INVALID,
i->gid_set ? i->gid : GID_INVALID) < 0)
if ((i->uid != st.st_uid || i->gid != st.st_gid) &&
(i->uid_set || i->gid_set)) {
log_debug("chown \"%s\" to "UID_FMT"."GID_FMT,
path,
i->uid_set ? i->uid : UID_INVALID,
i->gid_set ? i->gid : GID_INVALID);
if (chown(fn,
i->uid_set ? i->uid : UID_INVALID,
i->gid_set ? i->gid : GID_INVALID) < 0)
return log_error_errno(errno, "chown(%s) failed: %m", path);
}
}
fd = safe_close(fd);
return label_fix(path, false, false);
}
@ -712,10 +730,10 @@ static int parse_acls_from_arg(Item *item) {
}
#ifdef HAVE_ACL
static int path_set_acl(const char *path, acl_type_t type, acl_t acl, bool modify) {
static int path_set_acl(const char *path, const char *pretty, acl_type_t type, acl_t acl, bool modify) {
_cleanup_(acl_free_charpp) char *t = NULL;
_cleanup_(acl_freep) acl_t dup = NULL;
int r;
_cleanup_(acl_free_charpp) char *t = NULL;
/* Returns 0 for success, positive error if already warned,
* negative error otherwise. */
@ -741,9 +759,9 @@ static int path_set_acl(const char *path, acl_type_t type, acl_t acl, bool modif
return r;
t = acl_to_any_text(dup, NULL, ',', TEXT_ABBREVIATE);
log_debug("\"%s\": setting %s ACL \"%s\"", path,
log_debug("Setting %s ACL %s on %s.",
type == ACL_TYPE_ACCESS ? "access" : "default",
strna(t));
strna(t), pretty);
r = acl_set_file(path, type, dup);
if (r < 0)
@ -751,7 +769,7 @@ static int path_set_acl(const char *path, acl_type_t type, acl_t acl, bool modif
return -log_error_errno(errno,
"Setting %s ACL \"%s\" on %s failed: %m",
type == ACL_TYPE_ACCESS ? "access" : "default",
strna(t), path);
strna(t), pretty);
return 0;
}
@ -760,14 +778,32 @@ static int path_set_acl(const char *path, acl_type_t type, acl_t acl, bool modif
static int path_set_acls(Item *item, const char *path) {
int r = 0;
#ifdef HAVE_ACL
char fn[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
_cleanup_close_ int fd = -1;
struct stat st;
assert(item);
assert(path);
fd = open(path, O_RDONLY|O_NOFOLLOW|O_CLOEXEC|O_PATH|O_NOATIME);
if (fd < 0)
return log_error_errno(errno, "Adjusting ACL of %s failed: %m", path);
if (fstatat(fd, "", &st, AT_EMPTY_PATH) < 0)
return log_error_errno(errno, "Failed to fstat() file %s: %m", path);
if (S_ISLNK(st.st_mode)) {
log_debug("Skipping ACL fix for symlink %s.", path);
return 0;
}
xsprintf(fn, "/proc/self/fd/%i", fd);
if (item->acl_access)
r = path_set_acl(path, ACL_TYPE_ACCESS, item->acl_access, item->force);
r = path_set_acl(fn, path, ACL_TYPE_ACCESS, item->acl_access, item->force);
if (r == 0 && item->acl_default)
r = path_set_acl(path, ACL_TYPE_DEFAULT, item->acl_default, item->force);
r = path_set_acl(fn, path, ACL_TYPE_DEFAULT, item->acl_default, item->force);
if (r > 0)
return -r; /* already warned */
@ -891,9 +927,13 @@ static int path_set_attribute(Item *item, const char *path) {
if (!item->attribute_set || item->attribute_mask == 0)
return 0;
fd = open(path, O_RDONLY|O_NONBLOCK|O_CLOEXEC);
if (fd < 0)
fd = open(path, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOATIME|O_NOFOLLOW);
if (fd < 0) {
if (errno == ELOOP)
return log_error_errno(errno, "Skipping file attributes adjustment on symlink %s.", path);
return log_error_errno(errno, "Cannot open '%s': %m", path);
}
if (fstat(fd, &st) < 0)
return log_error_errno(errno, "Cannot stat '%s': %m", path);