When grow an array with bitmap to 4 TiB, the bitmap chunksize will be head /sys/block/md0/md/bitmap/chunksize <== 18446744071562067968
with 8 Tib, the chunksize is 4, which lead to assemble failure. The root cause is due to left shift count >= width of type and overflow.
The fix is simple, do a type cast before shift, the bug is pretty old since kernel 4.0 at least.
Cc: stable@vger.kernel.org Signed-off-by: Jack Wang jinpu.wang@ionos.com --- drivers/md/md-bitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index bf6dffadbe6f..b4d7a606a9d8 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2150,7 +2150,7 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, bitmap->counts.missing_pages = pages; bitmap->counts.chunkshift = chunkshift; bitmap->counts.chunks = chunks; - bitmap->mddev->bitmap_info.chunksize = 1 << (chunkshift + + bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift + BITMAP_BLOCK_SHIFT);
blocks = min(old_counts.chunks << old_counts.chunkshift,