diff --git a/src/shared/find-esp.c b/src/shared/find-esp.c index 1dbd1e8217..60f80387f8 100644 --- a/src/shared/find-esp.c +++ b/src/shared/find-esp.c @@ -238,12 +238,13 @@ static int verify_esp_udev( } static int verify_fsroot_dir( + int dir_fd, const char *path, bool searching, bool unprivileged_mode, dev_t *ret_dev) { - _cleanup_close_ int fd = -EBADF; + _cleanup_free_ char *f = NULL; STRUCT_NEW_STATX_DEFINE(sxa); STRUCT_NEW_STATX_DEFINE(sxb); int r; @@ -251,19 +252,22 @@ static int verify_fsroot_dir( /* Checks if the specified directory is at the root of its file system, and returns device * major/minor of the device, if it is. */ + assert(dir_fd >= 0); assert(path); - /* We are using O_PATH here, since that way we can operate on directory inodes we cannot look into, - * which is quite likely if we run unprivileged */ - fd = open(path, O_CLOEXEC|O_DIRECTORY|O_PATH); - if (fd < 0) - return log_full_errno((searching && errno == ENOENT) || - (unprivileged_mode && ERRNO_IS_PRIVILEGE(errno)) ? LOG_DEBUG : LOG_ERR, errno, - "Failed to open directory \"%s\": %m", path); + /* We pass the full path from the root directory file descriptor so we can use it for logging, but + * dir_fd points to the parent directory of the final component of the given path, so we extract the + * filename and operate on that. */ - r = statx_fallback(fd, "", AT_EMPTY_PATH, STATX_TYPE|STATX_INO|STATX_MNT_ID, &sxa.sx); + r = path_extract_filename(path, &f); + if (r < 0 && r != -EADDRNOTAVAIL) + return log_error_errno(r, "Failed to extract filename of %s: %m", path); + + r = statx_fallback(dir_fd, strempty(f), AT_SYMLINK_NOFOLLOW|(isempty(f) ? AT_EMPTY_PATH : 0), + STATX_TYPE|STATX_INO|STATX_MNT_ID, &sxa.sx); if (r < 0) - return log_full_errno((unprivileged_mode && ERRNO_IS_PRIVILEGE(r)) ? LOG_DEBUG : LOG_ERR, r, + return log_full_errno((searching && r == -ENOENT) || + (unprivileged_mode && ERRNO_IS_PRIVILEGE(r)) ? LOG_DEBUG : LOG_ERR, r, "Failed to determine block device node of \"%s\": %m", path); assert(S_ISDIR(sxa.sx.stx_mode)); /* We used O_DIRECTORY above, when opening, so this must hold */ @@ -283,29 +287,7 @@ static int verify_fsroot_dir( } /* Now let's look at the parent */ - r = statx_fallback(fd, "..", 0, STATX_TYPE|STATX_INO|STATX_MNT_ID, &sxb.sx); - if (r < 0 && ERRNO_IS_PRIVILEGE(r)) { - _cleanup_free_ char *parent = NULL; - - /* If going via ".." didn't work due to EACCESS, then let's determine the parent path - * directly instead. It's not as good, due to symlinks and such, but we can't do anything - * better here. - * - * (In case you wonder where this fallback is useful: consider a classic Fedora setup with - * /boot/ being an ext4 partition and /boot/efi/ being the VFAT ESP. The latter is mounted - * inaccessible for regular users via the dmask= mount option. In that case as unprivileged - * user we can stat() /boot/efi/, and we can stat()/enumerate /boot/. But we cannot look into - * /boot/efi/, and in particular not use /boot/efi/../ – hence this work-around.) */ - - if (path_equal(path, "/")) - goto success; - - r = path_extract_directory(path, &parent); - if (r < 0) - return log_error_errno(r, "Failed to extract parent path from '%s': %m", path); - - r = statx_fallback(AT_FDCWD, parent, AT_SYMLINK_NOFOLLOW, STATX_TYPE|STATX_INO|STATX_MNT_ID, &sxb.sx); - } + r = statx_fallback(dir_fd, "", AT_EMPTY_PATH, STATX_TYPE|STATX_INO|STATX_MNT_ID, &sxb.sx); if (r < 0) return log_full_errno(unprivileged_mode && ERRNO_IS_PRIVILEGE(r) ? LOG_DEBUG : LOG_ERR, r, "Failed to determine block device node of parent of \"%s\": %m", path); @@ -323,14 +305,16 @@ success: return 0; if (sxa.sx.stx_dev_major == 0) /* Hmm, maybe a btrfs device, and the caller asked for the backing device? Then let's try to get it. */ - return btrfs_get_block_device_fd(fd, ret_dev); + return btrfs_get_block_device_at(dir_fd, strempty(f), ret_dev); *ret_dev = makedev(sxa.sx.stx_dev_major, sxa.sx.stx_dev_minor); return 0; } static int verify_esp( - const char *p, + int rfd, + const char *path, + char **ret_path, uint32_t *ret_part, uint64_t *ret_pstart, uint64_t *ret_psize, @@ -340,10 +324,13 @@ static int verify_esp( bool relax_checks, searching = FLAGS_SET(flags, VERIFY_ESP_SEARCHING), unprivileged_mode = FLAGS_SET(flags, VERIFY_ESP_UNPRIVILEGED_MODE); + _cleanup_free_ char *p = NULL; + _cleanup_close_ int pfd = -EBADF; dev_t devid = 0; int r; - assert(p); + assert(rfd >= 0 || rfd == AT_FDCWD); + assert(path); /* This logs about all errors, except: * @@ -359,13 +346,25 @@ static int verify_esp( /* Non-root user can only check the status, so if an error occurred in the following, it does not cause any * issues. Let's also, silence the error messages. */ + r = chaseat(rfd, path, CHASE_AT_RESOLVE_IN_ROOT|CHASE_PARENT, &p, &pfd); + if (r < 0) + return log_full_errno((searching && r == -ENOENT) || + (unprivileged_mode && ERRNO_IS_PRIVILEGE(r)) ? LOG_DEBUG : LOG_ERR, + r, "Failed to open parent directory of \"%s\": %m", path); + if (!relax_checks) { + _cleanup_free_ char *f = NULL; struct statfs sfs; - if (statfs(p, &sfs) < 0) + r = path_extract_filename(p, &f); + if (r < 0 && r != -EADDRNOTAVAIL) + return log_error_errno(r, "Failed to extract filename of %s: %m", p); + + r = xstatfsat(pfd, strempty(f), &sfs); + if (r < 0) /* If we are searching for the mount point, don't generate a log message if we can't find the path */ - return log_full_errno((searching && errno == ENOENT) || - (unprivileged_mode && errno == EACCES) ? LOG_DEBUG : LOG_ERR, errno, + return log_full_errno((searching && r == -ENOENT) || + (unprivileged_mode && r == -EACCES) ? LOG_DEBUG : LOG_ERR, r, "Failed to check file system type of \"%s\": %m", p); if (!F_TYPE_EQUAL(sfs.f_type, MSDOS_SUPER_MAGIC)) @@ -378,7 +377,7 @@ static int verify_esp( relax_checks || detect_container() > 0; - r = verify_fsroot_dir(p, searching, unprivileged_mode, relax_checks ? NULL : &devid); + r = verify_fsroot_dir(pfd, p, searching, unprivileged_mode, relax_checks ? NULL : &devid); if (r < 0) return r; @@ -399,12 +398,16 @@ static int verify_esp( if (r < 0) return r; + if (ret_path) + *ret_path = TAKE_PTR(p); if (ret_devid) *ret_devid = devid; return 0; finish: + if (ret_path) + *ret_path = TAKE_PTR(p); if (ret_part) *ret_part = 0; if (ret_pstart) @@ -419,8 +422,8 @@ finish: return 0; } -int find_esp_and_warn( - const char *root, +int find_esp_and_warn_at( + int rfd, const char *path, bool unprivileged_mode, char **ret_path, @@ -430,9 +433,7 @@ int find_esp_and_warn( sd_id128_t *ret_uuid, dev_t *ret_devid) { - VerifyESPFlags flags = (unprivileged_mode ? VERIFY_ESP_UNPRIVILEGED_MODE : 0) | - (root ? VERIFY_ESP_RELAX_CHECKS : 0); - _cleanup_free_ char *p = NULL; + VerifyESPFlags flags = (unprivileged_mode ? VERIFY_ESP_UNPRIVILEGED_MODE : 0); int r; /* This logs about all errors except: @@ -441,48 +442,46 @@ int find_esp_and_warn( * -EACCESS → when unprivileged_mode is true, and we can't access something */ - if (path) { - r = chase(path, root, CHASE_PREFIX_ROOT, &p, NULL); - if (r < 0) - return log_error_errno(r, - "Failed to resolve path %s%s%s: %m", - path, - root ? " under directory " : "", - strempty(root)); + assert(rfd >= 0 || rfd == AT_FDCWD); - r = verify_esp(p, ret_part, ret_pstart, ret_psize, ret_uuid, ret_devid, flags); - if (r < 0) - return r; + if (rfd >= 0) + r = dir_fd_is_root(rfd); + else + r = true; + if (r < 0) + return log_error_errno(r, "Failed to check if directory file descriptor is root: %m"); + if (r == 0) + flags |= VERIFY_ESP_RELAX_CHECKS; - goto found; - } + if (path) + return verify_esp(rfd, path, ret_path, ret_part, ret_pstart, ret_psize, ret_uuid, ret_devid, flags); path = getenv("SYSTEMD_ESP_PATH"); if (path) { + _cleanup_free_ char *p = NULL; + _cleanup_close_ int fd = -EBADF; struct stat st; - r = chase(path, root, CHASE_PREFIX_ROOT, &p, NULL); - if (r < 0) - return log_error_errno(r, - "Failed to resolve path %s%s%s: %m", - path, - root ? " under directory " : "", - strempty(root)); - - if (!path_is_valid(p) || !path_is_absolute(p)) + if (!path_is_valid(path) || !path_is_absolute(path)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), - "$SYSTEMD_ESP_PATH does not refer to absolute path, refusing to use it: %s", - p); + "$SYSTEMD_ESP_PATH does not refer to an absolute path, refusing to use it: %s", + path); + + r = chaseat(rfd, path, CHASE_AT_RESOLVE_IN_ROOT, &p, &fd); + if (r < 0) + return log_error_errno(r, "Failed to resolve path %s: %m", path); /* Note: when the user explicitly configured things with an env var we won't validate the * path beyond checking it refers to a directory. After all we want this to be useful for * testing. */ - if (stat(p, &st) < 0) + if (fstat(fd, &st) < 0) return log_error_errno(errno, "Failed to stat '%s': %m", p); if (!S_ISDIR(st.st_mode)) return log_error_errno(SYNTHETIC_ERRNO(ENOTDIR), "ESP path '%s' is not a directory.", p); + if (ret_path) + *ret_path = TAKE_PTR(p); if (ret_part) *ret_part = 0; if (ret_pstart) @@ -494,36 +493,72 @@ int find_esp_and_warn( if (ret_devid) *ret_devid = st.st_dev; - goto found; + return 0; } FOREACH_STRING(dir, "/efi", "/boot", "/boot/efi") { - r = chase(dir, root, CHASE_PREFIX_ROOT, &p, NULL); - if (r == -ENOENT) - continue; - if (r < 0) - return log_error_errno(r, - "Failed to resolve path %s%s%s: %m", - dir, - root ? " under directory " : "", - strempty(root)); - - r = verify_esp(p, ret_part, ret_pstart, ret_psize, ret_uuid, ret_devid, + r = verify_esp(rfd, dir, ret_path, ret_part, ret_pstart, ret_psize, ret_uuid, ret_devid, flags | VERIFY_ESP_SEARCHING); if (r >= 0) - goto found; + return 0; if (!IN_SET(r, -ENOENT, -EADDRNOTAVAIL, -ENOTDIR, -ENOTTY)) /* This one is not it */ return r; - - p = mfree(p); } /* No logging here */ return -ENOKEY; +} -found: - if (ret_path) - *ret_path = TAKE_PTR(p); +int find_esp_and_warn( + const char *root, + const char *path, + bool unprivileged_mode, + char **ret_path, + uint32_t *ret_part, + uint64_t *ret_pstart, + uint64_t *ret_psize, + sd_id128_t *ret_uuid, + dev_t *ret_devid) { + + _cleanup_close_ int rfd = -EBADF; + _cleanup_free_ char *p = NULL; + uint32_t part; + uint64_t pstart, psize; + sd_id128_t uuid; + dev_t devid; + int r; + + rfd = open(empty_to_root(root), O_PATH|O_DIRECTORY|O_CLOEXEC); + if (rfd < 0) + return -errno; + + r = find_esp_and_warn_at(rfd, path, unprivileged_mode, + ret_path ? &p : NULL, + ret_part ? &part : NULL, + ret_pstart ? &pstart : NULL, + ret_psize ? &psize : NULL, + ret_uuid ? &uuid : NULL, + ret_devid ? &devid : NULL); + if (r < 0) + return r; + + if (ret_path) { + char *q = path_join(empty_to_root(root), p); + if (!q) + return -ENOMEM; + + *ret_path = TAKE_PTR(q); + } + if (ret_part) + *ret_part = part; + if (ret_pstart) + *ret_pstart = pstart; + if (ret_psize) + *ret_psize = psize; + if (ret_uuid) + *ret_uuid = uuid; + if (ret_devid) + *ret_devid = devid; return 0; } @@ -686,23 +721,34 @@ static int verify_xbootldr_udev( } static int verify_xbootldr( - const char *p, + int rfd, + const char *path, bool searching, bool unprivileged_mode, + char **ret_path, sd_id128_t *ret_uuid, dev_t *ret_devid) { + _cleanup_free_ char *p = NULL; + _cleanup_close_ int pfd = -EBADF; bool relax_checks; dev_t devid = 0; int r; - assert(p); + assert(rfd >= 0 || rfd == AT_FDCWD); + assert(path); + + r = chaseat(rfd, path, CHASE_AT_RESOLVE_IN_ROOT|CHASE_PARENT, &p, &pfd); + if (r < 0) + return log_full_errno((searching && r == -ENOENT) || + (unprivileged_mode && ERRNO_IS_PRIVILEGE(r)) ? LOG_DEBUG : LOG_ERR, + r, "Failed to open parent directory of \"%s\": %m", path); relax_checks = getenv_bool("SYSTEMD_RELAX_XBOOTLDR_CHECKS") > 0 || detect_container() > 0; - r = verify_fsroot_dir(p, searching, unprivileged_mode, relax_checks ? NULL : &devid); + r = verify_fsroot_dir(pfd, p, searching, unprivileged_mode, relax_checks ? NULL : &devid); if (r < 0) return r; @@ -716,12 +762,16 @@ static int verify_xbootldr( if (r < 0) return r; + if (ret_path) + *ret_path = TAKE_PTR(p); if (ret_devid) *ret_devid = devid; return 0; finish: + if (ret_path) + *ret_path = TAKE_PTR(p); if (ret_uuid) *ret_uuid = SD_ID128_NULL; if (ret_devid) @@ -730,85 +780,100 @@ finish: return 0; } -int find_xbootldr_and_warn( - const char *root, +int find_xbootldr_and_warn_at( + int rfd, const char *path, bool unprivileged_mode, char **ret_path, sd_id128_t *ret_uuid, dev_t *ret_devid) { - _cleanup_free_ char *p = NULL; int r; /* Similar to find_esp_and_warn(), but finds the XBOOTLDR partition. Returns the same errors. */ - if (path) { - r = chase(path, root, CHASE_PREFIX_ROOT, &p, NULL); - if (r < 0) - return log_error_errno(r, - "Failed to resolve path %s%s%s: %m", - path, - root ? " under directory " : "", - strempty(root)); + assert(rfd >= 0 || rfd == AT_FDCWD); - r = verify_xbootldr(p, /* searching= */ false, unprivileged_mode, ret_uuid, ret_devid); - if (r < 0) - return r; - - goto found; - } + if (path) + return verify_xbootldr(rfd, path, /* searching= */ false, unprivileged_mode, ret_path, ret_uuid, ret_devid); path = getenv("SYSTEMD_XBOOTLDR_PATH"); if (path) { + _cleanup_free_ char *p = NULL; + _cleanup_close_ int fd = -EBADF; struct stat st; - r = chase(path, root, CHASE_PREFIX_ROOT, &p, NULL); - if (r < 0) - return log_error_errno(r, - "Failed to resolve path %s%s%s: %m", - path, - root ? " under directory " : "", - strempty(root)); - - if (!path_is_valid(p) || !path_is_absolute(p)) + if (!path_is_valid(path) || !path_is_absolute(path)) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), - "$SYSTEMD_XBOOTLDR_PATH does not refer to absolute path, refusing to use it: %s", - p); + "$SYSTEMD_XBOOTLDR_PATH does not refer to an absolute path, refusing to use it: %s", + path); - if (stat(p, &st) < 0) + r = chaseat(rfd, path, CHASE_AT_RESOLVE_IN_ROOT, &p, &fd); + if (r < 0) + return log_error_errno(r, "Failed to resolve path %s: %m", p); + + if (fstat(fd, &st) < 0) return log_error_errno(errno, "Failed to stat '%s': %m", p); if (!S_ISDIR(st.st_mode)) return log_error_errno(SYNTHETIC_ERRNO(ENOTDIR), "XBOOTLDR path '%s' is not a directory.", p); + if (ret_path) + *ret_path = TAKE_PTR(p); if (ret_uuid) *ret_uuid = SD_ID128_NULL; if (ret_devid) *ret_devid = st.st_dev; - goto found; + return 0; } - r = chase("/boot", root, CHASE_PREFIX_ROOT, &p, NULL); - if (r == -ENOENT) + r = verify_xbootldr(rfd, "/boot", /* searching= */ true, unprivileged_mode, ret_path, ret_uuid, ret_devid); + if (r < 0) { + if (!IN_SET(r, -ENOENT, -EADDRNOTAVAIL, -ENOTDIR)) /* This one is not it */ + return r; + return -ENOKEY; + } + + return 0; +} + +int find_xbootldr_and_warn( + const char *root, + const char *path, + bool unprivileged_mode, + char **ret_path, + sd_id128_t *ret_uuid, + dev_t *ret_devid) { + + _cleanup_close_ int rfd = -EBADF; + _cleanup_free_ char *p = NULL; + sd_id128_t uuid; + dev_t devid; + int r; + + rfd = open(empty_to_root(root), O_PATH|O_DIRECTORY|O_CLOEXEC); + if (rfd < 0) + return -errno; + + r = find_xbootldr_and_warn_at(rfd, path, unprivileged_mode, + ret_path ? &p : NULL, + ret_uuid ? &uuid : NULL, + ret_devid ? &devid : NULL); if (r < 0) - return log_error_errno(r, - "Failed to resolve path /boot%s%s: %m", - root ? " under directory " : "", - strempty(root)); - - r = verify_xbootldr(p, /* searching= */ true, unprivileged_mode, ret_uuid, ret_devid); - if (r >= 0) - goto found; - if (!IN_SET(r, -ENOENT, -EADDRNOTAVAIL, -ENOTDIR)) /* This one is not it */ return r; - return -ENOKEY; + if (ret_path) { + char *q = path_join(empty_to_root(root), p); + if (!q) + return -ENOMEM; -found: - if (ret_path) - *ret_path = TAKE_PTR(p); + *ret_path = TAKE_PTR(q); + } + if (ret_uuid) + *ret_uuid = uuid; + if (ret_devid) + *ret_devid = devid; return 0; } diff --git a/src/shared/find-esp.h b/src/shared/find-esp.h index 78d7f4551e..94f320195b 100644 --- a/src/shared/find-esp.h +++ b/src/shared/find-esp.h @@ -8,5 +8,8 @@ #include "sd-id128.h" +int find_esp_and_warn_at(int rfd, const char *path, bool unprivileged_mode, char **ret_path, uint32_t *ret_part, uint64_t *ret_pstart, uint64_t *ret_psize, sd_id128_t *ret_uuid, dev_t *ret_devid); int find_esp_and_warn(const char *root, const char *path, bool unprivileged_mode, char **ret_path, uint32_t *ret_part, uint64_t *ret_pstart, uint64_t *ret_psize, sd_id128_t *ret_uuid, dev_t *ret_devid); + +int find_xbootldr_and_warn_at(int rfd, const char *path, bool unprivileged_mode, char **ret_path, sd_id128_t *ret_uuid, dev_t *ret_devid); int find_xbootldr_and_warn(const char *root, const char *path, bool unprivileged_mode, char **ret_path, sd_id128_t *ret_uuid, dev_t *ret_devid);