From: Michael Bommarito Date: Tue, 19 May 2026 11:04:02 +0000 (-0400) Subject: ocfs2: reject dinodes with non-canonical i_mode type X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5366a017099c6a3c443be908a05f26fd72af12a1;p=thirdparty%2Flinux.git ocfs2: reject dinodes with non-canonical i_mode type Patch series "ocfs2: harden inode validators against forged metadata", v2. This series adds three structural checks to OCFS2 dinode validation so malformed on-disk fields are rejected before ocfs2_populate_inode() copies them into the in-core inode. The checks cover: - i_mode values whose type bits do not name a canonical POSIX file type; - non-device dinodes whose id1.dev1.i_rdev field is non-zero; and - non-inline dinodes that claim non-zero i_size while i_clusters is zero, covering directories unconditionally and regular files on non-sparse volumes. The normal read path reports these through ocfs2_error(), matching the existing suballoc-slot, inline-data, chain-list, and refcount checks. The online filecheck path uses the same structural predicates but keeps its own reporting contract, returning OCFS2_FILECHECK_ERR_INVALIDINO instead of calling ocfs2_error(). This patch (of 3): ocfs2_validate_inode_block() currently accepts any non-zero i_mode value. ocfs2_populate_inode() then copies that mode verbatim into inode->i_mode and dispatches on i_mode & S_IFMT to the file/dir/symlink/special_file iops; an unrecognised type falls through to ocfs2_special_file_iops and init_special_inode(). Reject dinodes whose type bits do not name one of the seven canonical POSIX file types. Use fs_umode_to_ftype(), the same generic file-type conversion helper OCFS2 already uses for directory entries, so the accepted inode type set matches the kernel file-type vocabulary instead of open-coding a local switch. Apply the same structural check to the online filecheck read path. filecheck keeps its own error namespace, so it reports malformed i_mode through the filecheck logger and OCFS2_FILECHECK_ERR_INVALIDINO instead of calling ocfs2_error(), but it must not allow a malformed dinode to proceed into ocfs2_populate_inode(). Link: https://lore.kernel.org/20260519110404.1803902-1-michael.bommarito@gmail.com Link: https://lore.kernel.org/20260519110404.1803902-2-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: Changwei Ge Cc: Heming Zhao Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Cc: Signed-off-by: Andrew Morton --- diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index a510a0eb1adc..e149ccbdc03c 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -13,6 +13,7 @@ #include #include #include +#include #include @@ -64,7 +65,12 @@ static int ocfs2_filecheck_read_inode_block_full(struct inode *inode, static int ocfs2_filecheck_validate_inode_block(struct super_block *sb, struct buffer_head *bh); static int ocfs2_filecheck_repair_inode_block(struct super_block *sb, - struct buffer_head *bh); + struct buffer_head *bh); + +static bool ocfs2_valid_inode_mode(umode_t mode) +{ + return fs_umode_to_ftype(mode) != FT_UNKNOWN; +} void ocfs2_set_inode_flags(struct inode *inode) { @@ -1494,6 +1500,24 @@ int ocfs2_validate_inode_block(struct super_block *sb, goto bail; } + /* + * Reject dinodes whose i_mode does not name one of the seven + * canonical POSIX file types. ocfs2_populate_inode() copies + * i_mode verbatim into inode->i_mode and then dispatches via + * switch (mode & S_IFMT) to file/dir/symlink/special_file iops; + * an unrecognised type falls into ocfs2_special_file_iops with + * init_special_inode(), which interprets i_rdev. Constrain the + * type here so the dispatch only ever sees a value mkfs.ocfs2 / + * VFS can produce. + */ + if (!ocfs2_valid_inode_mode(le16_to_cpu(di->i_mode))) { + rc = ocfs2_error(sb, + "Invalid dinode #%llu: mode 0%o has unknown file type\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(di->i_mode)); + goto bail; + } + if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) { struct ocfs2_inline_data *data = &di->id2.i_data; @@ -1624,6 +1648,15 @@ static int ocfs2_filecheck_validate_inode_block(struct super_block *sb, (unsigned long long)bh->b_blocknr, le32_to_cpu(di->i_fs_generation)); rc = -OCFS2_FILECHECK_ERR_GENERATION; + goto bail; + } + + if (!ocfs2_valid_inode_mode(le16_to_cpu(di->i_mode))) { + mlog(ML_ERROR, + "Filecheck: invalid dinode #%llu: mode 0%o has unknown file type\n", + (unsigned long long)bh->b_blocknr, + le16_to_cpu(di->i_mode)); + rc = -OCFS2_FILECHECK_ERR_INVALIDINO; } bail: @@ -1812,4 +1845,3 @@ const struct ocfs2_caching_operations ocfs2_inode_caching_ops = { .co_io_lock = ocfs2_inode_cache_io_lock, .co_io_unlock = ocfs2_inode_cache_io_unlock, }; -