Commit e35fa567 authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds
Browse files

hfsplus: use struct_group_attr() for memcpy() region 

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Add struct_group() to mark the "info" region (containing struct DInfo
and struct DXInfo structs) in struct hfsplus_cat_folder and struct
hfsplus_cat_file that are written into directly, so the compiler can
correctly reason about the expected size of the writes.

"pahole" shows no size nor member offset changes to struct
hfsplus_cat_folder nor struct hfsplus_cat_file.  "objdump -d" shows no
object code changes.

Link: https://lkml.kernel.org/r/20211119192851.1046717-1-keescook@chromium.org


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e1ce8a97

fs/hfsplus/hfsplus_raw.h

+8 −4
Original line number Diff line number Diff line
@@ -260,8 +260,10 @@ struct hfsplus_cat_folder { 
	__be32 access_date;

	__be32 backup_date;

	struct hfsplus_perm permissions;

	struct_group_attr(info, __packed,

		struct DInfo user_info;

		struct DXInfo finder_info;

	);

	__be32 text_encoding;

	__be32 subfolders;	/* Subfolder count in HFSX. Reserved in HFS+. */

} __packed;
@@ -294,8 +296,10 @@ struct hfsplus_cat_file { 
	__be32 access_date;

	__be32 backup_date;

	struct hfsplus_perm permissions;

	struct_group_attr(info, __packed,

		struct FInfo user_info;

		struct FXInfo finder_info;

	);

	__be32 text_encoding;

	u32 reserved2;

fs/hfsplus/xattr.c

+2 −2
Original line number Diff line number Diff line
@@ -296,7 +296,7 @@ int __hfsplus_setxattr(struct inode *inode, const char *name, 
					sizeof(hfsplus_cat_entry));

		if (be16_to_cpu(entry.type) == HFSPLUS_FOLDER) {

			if (size == folder_finderinfo_len) {

				memcpy(&entry.folder.user_info, value,

				memcpy(&entry.folder.info, value,

						folder_finderinfo_len);

				hfs_bnode_write(cat_fd.bnode, &entry,

					cat_fd.entryoffset,
@@ -309,7 +309,7 @@ int __hfsplus_setxattr(struct inode *inode, const char *name, 
			}

		} else if (be16_to_cpu(entry.type) == HFSPLUS_FILE) {

			if (size == file_finderinfo_len) {

				memcpy(&entry.file.user_info, value,

				memcpy(&entry.file.info, value,

						file_finderinfo_len);

				hfs_bnode_write(cat_fd.bnode, &entry,

					cat_fd.entryoffset,