2 files changed, 19 insertions, 8 deletions

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 4c01c7535fb5..556acff3952f 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -191,6 +191,11 @@ int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
                 return -EINVAL;
         }
 
+        if (chunk_size_ulong > INT_MAX >> SECTOR_SHIFT) {
+                *error = "Chunk size is too high";
+                return -EINVAL;
+        }
+
         store->chunk_size = chunk_size_ulong;
         store->chunk_mask = chunk_size_ulong - 1;
         store->chunk_shift = ffs(chunk_size_ulong) - 1;
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 5d1a97580cb7..d5b2e08750d5 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -286,6 +286,7 @@ static int read_header(struct pstore *ps, int *new_snapshot)
         struct disk_header *dh;
         chunk_t chunk_size;
         int chunk_size_supplied = 1;
+        char *chunk_err;
 
         /*
          * Use default chunk size (or hardsect_size, if larger) if none supplied
@@ -329,20 +330,25 @@ static int read_header(struct pstore *ps, int *new_snapshot)
         ps->version = le32_to_cpu(dh->version);
         chunk_size = le32_to_cpu(dh->chunk_size);
 
-        if (!chunk_size_supplied || ps->store->chunk_size == chunk_size)
+        if (ps->store->chunk_size == chunk_size)
                 return 0;
 
-        DMWARN("chunk size %llu in device metadata overrides "
-               "table chunk size of %llu.",
-               (unsigned long long)chunk_size,
-               (unsigned long long)ps->store->chunk_size);
+        if (chunk_size_supplied)
+                DMWARN("chunk size %llu in device metadata overrides "
+                       "table chunk size of %llu.",
+                       (unsigned long long)chunk_size,
+                       (unsigned long long)ps->store->chunk_size);
 
         /* We had a bogus chunk_size. Fix stuff up. */
         free_area(ps);
 
-        ps->store->chunk_size = chunk_size;
-        ps->store->chunk_mask = chunk_size - 1;
-        ps->store->chunk_shift = ffs(chunk_size) - 1;
+        r = dm_exception_store_set_chunk_size(ps->store, chunk_size,
+                                              &chunk_err);
+        if (r) {
+                DMERR("invalid on-disk chunk size %llu: %s.",
+                      (unsigned long long)chunk_size, chunk_err);
+                return r;
+        }
 
         r = dm_io_client_resize(sectors_to_pages(ps->store->chunk_size),
                                 ps->io_client);