diff options
| -rw-r--r-- | sys/geom/geom_vol_ffs.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/sys/geom/geom_vol_ffs.c b/sys/geom/geom_vol_ffs.c index 94175f74e236..d90222f7f6e7 100644 --- a/sys/geom/geom_vol_ffs.c +++ b/sys/geom/geom_vol_ffs.c @@ -88,6 +88,16 @@ g_vol_ffs_taste(struct g_class *mp, struct g_provider *pp, int flags) * provider based on that. */ for (sb=0; (superblock = superblocks[sb]) != -1; sb++) { + /* + * Take care not to issue an invalid I/O request. The + * offset and size of the superblock candidate must be + * multiples of the provider's sector size, otherwise an + * FFS can't exist on the provider anyway. + */ + if (superblock % cp->provider->sectorsize != 0 || + SBLOCKSIZE % cp->provider->sectorsize != 0) + continue; + fs = (struct fs *) g_read_data(cp, superblock, SBLOCKSIZE, &error); if (fs == NULL || error != 0) |