From: Ryusuke Konishi Date: Wed, 4 Sep 2024 08:13:08 +0000 (+0900) Subject: nilfs2: determine empty node blocks as corrupted X-Git-Tag: v6.12-rc1~114^2~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=111b812d3662f3a1b831d19208f83aa711583fe6;p=thirdparty%2Fkernel%2Flinux.git nilfs2: determine empty node blocks as corrupted Due to the nature of b-trees, nilfs2 itself and admin tools such as mkfs.nilfs2 will never create an intermediate b-tree node block with 0 child nodes, nor will they delete (key, pointer)-entries that would result in such a state. However, it is possible that a b-tree node block is corrupted on the backing device and is read with 0 child nodes. Because operation is not guaranteed if the number of child nodes is 0 for intermediate node blocks other than the root node, modify nilfs_btree_node_broken(), which performs sanity checks when reading a b-tree node block, so that such cases will be judged as metadata corruption. Link: https://lkml.kernel.org/r/20240904081401.16682-3-konishi.ryusuke@gmail.com Fixes: 17c76b0104e4 ("nilfs2: B-tree based block mapping") Signed-off-by: Ryusuke Konishi Cc: Lizhi Xu Signed-off-by: Andrew Morton --- diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index d390b8ba00d45..dedd3c4808423 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -350,7 +350,7 @@ static int nilfs_btree_node_broken(const struct nilfs_btree_node *node, if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN || level >= NILFS_BTREE_LEVEL_MAX || (flags & NILFS_BTREE_NODE_ROOT) || - nchildren < 0 || + nchildren <= 0 || nchildren > NILFS_BTREE_NODE_NCHILDREN_MAX(size))) { nilfs_crit(inode->i_sb, "bad btree node (ino=%lu, blocknr=%llu): level = %d, flags = 0x%x, nchildren = %d",