From f6089ff87d309a8ddb7b0d4dd92a570f1b0f689b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 14 Oct 2010 09:54:28 -0400 Subject: hfsplus: fix link corruption HFS implements hardlink by using indirect catalog entries that refer to a hidden directly. The link target is cached in the dev field in the HFS+ specific inode, which is also used for the device number for device files, and inside for passing the nlink value of the indirect node from hfsplus_cat_write_inode to a helper function. Now if we happen to write out the indirect node while hfsplus_link is creating the catalog entry we'll get a link pointing to the linkid of the current nlink value. This can easily be reproduced by a large enough loop of local git-clone operations. Stop abusing the dev field in the HFS+ inode for short term storage by refactoring the way the permission structure in the catalog entry is set up, and rename the dev field to linkid to avoid any confusion. While we're at it also prevent creating hard links to special files, as the HFS+ dev and linkid share the same space in the on-disk structure. Signed-off-by: Christoph Hellwig --- fs/hfsplus/catalog.c | 2 +- fs/hfsplus/dir.c | 6 ++++-- fs/hfsplus/hfsplus_fs.h | 8 +++++--- fs/hfsplus/inode.c | 14 ++++++++------ 4 files changed, 18 insertions(+), 12 deletions(-) (limited to 'fs') diff --git a/fs/hfsplus/catalog.c b/fs/hfsplus/catalog.c index 48979c4e8fa5..9d1594b0a07a 100644 --- a/fs/hfsplus/catalog.c +++ b/fs/hfsplus/catalog.c @@ -134,7 +134,7 @@ static int hfsplus_cat_build_record(hfsplus_cat_entry *entry, u32 cnid, struct i file->user_info.fdCreator = cpu_to_be32(HFSP_HFSPLUS_CREATOR); file->user_info.fdFlags = cpu_to_be16(0x100); file->create_date = HFSPLUS_I(sbi->hidden_dir)->create_date; - file->permissions.dev = cpu_to_be32(HFSPLUS_I(inode)->dev); + file->permissions.dev = cpu_to_be32(HFSPLUS_I(inode)->linkid); } return sizeof(*file); } diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c index 33aab211695a..c05c8776e836 100644 --- a/fs/hfsplus/dir.c +++ b/fs/hfsplus/dir.c @@ -102,7 +102,7 @@ again: if (IS_ERR(inode)) return ERR_CAST(inode); if (S_ISREG(inode->i_mode)) - HFSPLUS_I(inode)->dev = linkid; + HFSPLUS_I(inode)->linkid = linkid; out: d_add(dentry, inode); return NULL; @@ -252,6 +252,8 @@ static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir, if (HFSPLUS_IS_RSRC(inode)) return -EPERM; + if (!S_ISREG(inode->i_mode)) + return -EPERM; mutex_lock(&sbi->vh_mutex); if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) { @@ -268,7 +270,7 @@ static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir, if (res != -EEXIST) goto out; } - HFSPLUS_I(inode)->dev = id; + HFSPLUS_I(inode)->linkid = id; cnid = sbi->next_cnid++; src_dentry->d_fsdata = (void *)(unsigned long)cnid; res = hfsplus_create_cat(cnid, src_dir, &src_dentry->d_name, inode); diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h index 5cda96366acf..d92f590d6633 100644 --- a/fs/hfsplus/hfsplus_fs.h +++ b/fs/hfsplus/hfsplus_fs.h @@ -178,7 +178,11 @@ struct hfsplus_inode_info { */ struct inode *rsrc_inode; __be32 create_date; - u32 dev; + + /* + * Protected by sbi->vh_mutex. + */ + u32 linkid; /* * Protected by i_mutex. @@ -427,6 +431,4 @@ static inline struct hfsplus_inode_info *HFSPLUS_I(struct inode *inode) #define hfsp_ut2mt(t) __hfsp_ut2mt((t).tv_sec) #define hfsp_now2mt() __hfsp_ut2mt(get_seconds()) -#define kdev_t_to_nr(x) (x) - #endif diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c index a05b3afa7230..746e0ee20717 100644 --- a/fs/hfsplus/inode.c +++ b/fs/hfsplus/inode.c @@ -267,7 +267,13 @@ static void hfsplus_set_perms(struct inode *inode, struct hfsplus_perm *perms) perms->mode = cpu_to_be16(inode->i_mode); perms->owner = cpu_to_be32(inode->i_uid); perms->group = cpu_to_be32(inode->i_gid); - perms->dev = cpu_to_be32(HFSPLUS_I(inode)->dev); + + if (S_ISREG(inode->i_mode)) + perms->dev = cpu_to_be32(inode->i_nlink); + else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) + perms->dev = cpu_to_be32(inode->i_rdev); + else + perms->dev = 0; } static int hfsplus_file_open(struct inode *inode, struct file *file) @@ -491,7 +497,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd) type = hfs_bnode_read_u16(fd->bnode, fd->entryoffset); - HFSPLUS_I(inode)->dev = 0; + HFSPLUS_I(inode)->linkid = 0; if (type == HFSPLUS_FOLDER) { struct hfsplus_cat_folder *folder = &entry.folder; @@ -595,10 +601,6 @@ int hfsplus_cat_write_inode(struct inode *inode) hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, sizeof(struct hfsplus_cat_file)); hfsplus_inode_write_fork(inode, &file->data_fork); - if (S_ISREG(inode->i_mode)) - HFSPLUS_I(inode)->dev = inode->i_nlink; - if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) - HFSPLUS_I(inode)->dev = kdev_t_to_nr(inode->i_rdev); hfsplus_set_perms(inode, &file->permissions); if ((file->permissions.rootflags | file->permissions.userflags) & HFSPLUS_FLG_IMMUTABLE) file->flags |= cpu_to_be16(HFSPLUS_FILE_LOCKED); -- cgit v1.2.3-58-ga151