From: Michael Bommarito Date: Tue, 19 May 2026 11:04:04 +0000 (-0400) Subject: ocfs2: reject non-inline dinodes with i_size and zero i_clusters X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ebc672fab7a76e1e47e0f2fc1ee48118d27fde4;p=thirdparty%2Fkernel%2Flinux.git ocfs2: reject non-inline dinodes with i_size and zero i_clusters On a volume mounted without OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC, a non-inline regular file with non-zero i_size and zero i_clusters is structurally malformed: the extent map declares no allocated clusters yet the size header claims content exists. Keep rejecting that shape, but express it through a shared predicate so the same invariant is available to normal inode reads and online filecheck. The same zero-cluster shape is also malformed for non-inline directories. ocfs2 directory growth allocates backing storage before advancing i_size, and ocfs2_dir_foreach_blk_el() later walks until ctx->pos reaches i_size_read(inode). A forged directory dinode with a huge i_size and no clusters would repeatedly fail on holes while advancing through the claimed size. Sparse regular files remain exempt: on sparse-alloc volumes, truncate can legitimately grow i_size without allocating clusters. System inodes and inline-data dinodes also retain their separate storage rules. Mirror the check in ocfs2_filecheck_validate_inode_block() as well. filecheck reports through its own error namespace, so malformed size/cluster state is logged as a filecheck invalid-inode result rather than via ocfs2_error(), but it must not proceed into ocfs2_populate_inode(). Link: https://lore.kernel.org/20260519110404.1803902-4-michael.bommarito@gmail.com Fixes: b657c95c1108 ("ocfs2: Wrap inode block reads in a dedicated function.") Signed-off-by: Michael Bommarito Link: https://sashiko.dev/#/patchset/20260517111015.3187935-1-michael.bommarito%40gmail.com Assisted-by: Claude:claude-opus-4-7 Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Cc: Signed-off-by: Andrew Morton --- diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 992980ea9804..432eac01c176 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -82,6 +82,24 @@ static bool ocfs2_dinode_has_unexpected_rdev(struct ocfs2_dinode *di) return !S_ISCHR(mode) && !S_ISBLK(mode) && di->id1.dev1.i_rdev != 0; } +static bool ocfs2_dinode_has_size_without_clusters(struct super_block *sb, + struct ocfs2_dinode *di) +{ + umode_t mode = le16_to_cpu(di->i_mode); + + if (le32_to_cpu(di->i_flags) & OCFS2_SYSTEM_FL) + return false; + if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) + return false; + if (!le64_to_cpu(di->i_size) || le32_to_cpu(di->i_clusters)) + return false; + + if (S_ISDIR(mode)) + return true; + + return !ocfs2_sparse_alloc(OCFS2_SB(sb)) && S_ISREG(mode); +} + void ocfs2_set_inode_flags(struct inode *inode) { unsigned int flags = OCFS2_I(inode)->ip_attr; @@ -1563,6 +1581,33 @@ int ocfs2_validate_inode_block(struct super_block *sb, goto bail; } + /* + * Non-inline directories must not have i_size without allocated + * clusters: directory growth adds storage before advancing i_size, + * and readdir walks i_size block-by-block. A forged directory + * with zero clusters and a huge i_size would repeatedly fault on + * holes while advancing through the claimed size. + * + * Non-inline regular files have the same invariant on non-sparse + * volumes. Sparse regular files are different: truncate can + * legitimately grow i_size without allocating clusters, so keep + * the sparse-alloc carveout for S_IFREG only. System inodes and + * inline-data dinodes have their own storage rules. + */ + if (ocfs2_dinode_has_size_without_clusters(sb, di)) { + if (S_ISDIR(le16_to_cpu(di->i_mode))) + rc = ocfs2_error(sb, + "Invalid dinode #%llu: directory i_size %llu with i_clusters 0 and no inline-data flag\n", + (unsigned long long)bh->b_blocknr, + (unsigned long long)le64_to_cpu(di->i_size)); + else + rc = ocfs2_error(sb, + "Invalid dinode #%llu: regular file i_size %llu with i_clusters 0 and no inline-data flag on non-sparse volume\n", + (unsigned long long)bh->b_blocknr, + (unsigned long long)le64_to_cpu(di->i_size)); + goto bail; + } + if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) { struct ocfs2_inline_data *data = &di->id2.i_data; @@ -1712,6 +1757,21 @@ static int ocfs2_filecheck_validate_inode_block(struct super_block *sb, le16_to_cpu(di->i_mode), (unsigned long long)le64_to_cpu(di->id1.dev1.i_rdev)); rc = -OCFS2_FILECHECK_ERR_INVALIDINO; + goto bail; + } + + if (ocfs2_dinode_has_size_without_clusters(sb, di)) { + if (S_ISDIR(le16_to_cpu(di->i_mode))) + mlog(ML_ERROR, + "Filecheck: invalid dinode #%llu: directory i_size %llu with i_clusters 0 and no inline-data flag\n", + (unsigned long long)bh->b_blocknr, + (unsigned long long)le64_to_cpu(di->i_size)); + else + mlog(ML_ERROR, + "Filecheck: invalid dinode #%llu: regular file i_size %llu with i_clusters 0 and no inline-data flag on non-sparse volume\n", + (unsigned long long)bh->b_blocknr, + (unsigned long long)le64_to_cpu(di->i_size)); + rc = -OCFS2_FILECHECK_ERR_INVALIDINO; } bail: