From af7293fe8a6d7b9af70f90b1ccdc91a0e2fec7f8 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 30 Mar 2020 11:09:32 +0200 Subject: [PATCH] ext2fs: fix off-by-one in dx_grow_tree() There is an off-by-one error in dx_grow_tree() when checking whether we can add another level to the tree. Thus we can grow tree too much leading to possible crashes in the library or corrupted filesystem. Fix the bug. Signed-off-by: Jan Kara Reviewed-by: Lukas Czerner Signed-off-by: Theodore Ts'o --- lib/ext2fs/link.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/ext2fs/link.c b/lib/ext2fs/link.c index 7b5bb02..469eea8 100644 --- a/lib/ext2fs/link.c +++ b/lib/ext2fs/link.c @@ -473,7 +473,7 @@ static errcode_t dx_grow_tree(ext2_filsys fs, ext2_ino_t dir, ext2fs_le16_to_cpu(info->frames[i].head->limit)) break; /* Need to grow tree depth? */ - if (i < 0 && info->levels > ext2_dir_htree_level(fs)) + if (i < 0 && info->levels >= ext2_dir_htree_level(fs)) return EXT2_ET_DIR_NO_SPACE; lblk = size / fs->blocksize; size += fs->blocksize; -- 1.8.3.1