xfs_scrub: check label for misleading characters

Make sure that we can retrieve the label and that it doesn't contain
anything potentially misleading.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/scrub/phase5.c b/scrub/phase5.c
index 6ffcec2d70c93a5f99ba87a7772fba759b0ffd26..49886e6feefd6ac3d20200307edacaeb7d8fbf4b 100644 (file)
--- a/scrub/phase5.c
+++ b/scrub/phase5.c
@@ -11,6 +11,7 @@
 #ifdef HAVE_LIBATTR
 # include <attr/attributes.h>
 #endif
+#include <linux/fs.h>
 #include "handle.h"
 #include "list.h"
 #include "path.h"
@@ -282,6 +283,55 @@ out:
        return *pmoveon ? 0 : XFS_ITERATE_INODES_ABORT;
 }
 
+#ifndef FS_IOC_GETFSLABEL
+# define FSLABEL_MAX           256
+# define FS_IOC_GETFSLABEL     _IOR(0x94, 49, char[FSLABEL_MAX])
+#endif /* FS_IOC_GETFSLABEL */
+
+/*
+ * Check the filesystem label for Unicode normalization problems or misleading
+ * sequences.
+ */
+static bool
+xfs_scrub_fs_label(
+       struct scrub_ctx                *ctx)
+{
+       char                            label[FSLABEL_MAX];
+       struct unicrash                 *uc = NULL;
+       bool                            moveon = true;
+       int                             error;
+
+       moveon = unicrash_fs_label_init(&uc, ctx);
+       if (!moveon)
+               return false;
+
+       /* Retrieve label; quietly bail if we don't support that. */
+       error = ioctl(ctx->mnt_fd, FS_IOC_GETFSLABEL, &label);
+       if (error) {
+               if (errno != EOPNOTSUPP && errno != ENOTTY) {
+                       moveon = false;
+                       perror(ctx->mntpoint);
+               }
+               goto out;
+       }
+
+       /* Ignore empty labels. */
+       if (label[0] == 0)
+               goto out;
+
+       /* Otherwise check for weirdness. */
+       if (uc)
+               moveon = unicrash_check_fs_label(uc, ctx->mntpoint, label);
+       else
+               moveon = xfs_scrub_check_name(ctx, ctx->mntpoint,
+                               _("filesystem label"), label);
+       if (!moveon)
+               goto out;
+out:
+       unicrash_free(uc);
+       return moveon;
+}
+
 /* Check directory connectivity. */
 bool
 xfs_scan_connections(
@@ -296,6 +346,10 @@ _("Filesystem has errors, skipping connectivity checks."));
                return true;
        }
 
+       moveon = xfs_scrub_fs_label(ctx);
+       if (!moveon)
+               return false;
+
        ret = xfs_scan_all_inodes(ctx, xfs_scrub_connections, &moveon);
        if (!ret)
                moveon = false;

diff --git a/scrub/unicrash.c b/scrub/unicrash.c
index a95fc3057d9a5c1e728dae8e4f783d476813e046..121eedbce7c944d70367c70b9d53bd5c9dbe0c57 100644 (file)
--- a/scrub/unicrash.c
+++ b/scrub/unicrash.c
@@ -465,6 +465,15 @@ unicrash_xattr_init(
                        is_only_root_writable(bstat));
 }
 
+/* Initialize the collision detector for a filesystem label. */
+bool
+unicrash_fs_label_init(
+       struct unicrash         **ucp,
+       struct scrub_ctx        *ctx)
+{
+       return unicrash_init(ucp, ctx, false, 16, true);
+}
+
 /* Free the crash detector. */
 void
 unicrash_free(
@@ -698,3 +707,18 @@ unicrash_check_xattr_name(
        return __unicrash_check_name(uc, descr, _("extended attribute"),
                        attrname, 0);
 }
+
+/*
+ * Check the fs label for unicode normalization problems or misleading bits.
+ */
+bool
+unicrash_check_fs_label(
+       struct unicrash         *uc,
+       const char              *descr,
+       const char              *label)
+{
+       if (!uc)
+               return true;
+       return __unicrash_check_name(uc, descr, _("filesystem label"),
+                       label, 0);
+}

diff --git a/scrub/unicrash.h b/scrub/unicrash.h
index 7d7276a8c7e10790512cba480e65e6614914bd92..85fcabc6f44d14f358cd8536e8d3b313c3b960e2 100644 (file)
--- a/scrub/unicrash.h
+++ b/scrub/unicrash.h
@@ -17,17 +17,22 @@ bool unicrash_dir_init(struct unicrash **ucp, struct scrub_ctx *ctx,
                struct xfs_bstat *bstat);
 bool unicrash_xattr_init(struct unicrash **ucp, struct scrub_ctx *ctx,
                struct xfs_bstat *bstat);
+bool unicrash_fs_label_init(struct unicrash **ucp, struct scrub_ctx *ctx);
 void unicrash_free(struct unicrash *uc);
 bool unicrash_check_dir_name(struct unicrash *uc, const char *descr,
                struct dirent *dirent);
 bool unicrash_check_xattr_name(struct unicrash *uc, const char *descr,
                const char *attrname);
+bool unicrash_check_fs_label(struct unicrash *uc, const char *descr,
+               const char *label);
 #else
 # define unicrash_dir_init(u, c, b)            (true)
 # define unicrash_xattr_init(u, c, b)          (true)
+# define unicrash_label_init(u, c)             (true)
 # define unicrash_free(u)                      do {(u) = (u);} while (0)
 # define unicrash_check_dir_name(u, d, n)      (true)
 # define unicrash_check_xattr_name(u, d, n)    (true)
+# define unicrash_check_fs_label(u, d, n)      (true)
 #endif /* HAVE_LIBICU */
 
 #endif /* XFS_SCRUB_UNICRASH_H_ */