From: Zhihao Cheng chengzhihao1@huawei.com
maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9MWEQ CVE: NA
Reference: https://lore.kernel.org/lkml/20240410073751.2522830-8-chengzhihao1@huawei.co...
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For selinux or encryption scenarios, UBIFS could become inconsistent while creating new files in powercut case. Encryption/selinux related xattrs will be created before creating file dentry, which makes creation process is not atomic, details are shown as:
Encryption case: ubifs_create ubifs_new_inode fscrypt_set_context ubifs_xattr_set create_xattr ubifs_jnl_update // Disk: xentry xinode inode(LAST_OF_NODE_GROUP)
power cut <<
ubifs_jnl_update // Disk: dentry inode parent_inode(LAST_OF_NODE_GROUP)
Selinux case: ubifs_create ubifs_new_inode ubifs_init_security security_inode_init_security ubifs_xattr_set create_xattr ubifs_jnl_update // Disk: xentry xinode inode(LAST_OF_NODE_GROUP)
power cut <<
ubifs_jnl_update // Disk: dentry inode parent_inode(LAST_OF_NODE_GROUP)
Above process will make chk_fs failed in next mounting: UBIFS error (ubi0:0 pid 7995): dbg_check_filesystem [ubifs]: inode 66 nlink is 1, but calculated nlink is 0
Fix it by allocating orphan inode for each non-xattr file creation, then removing orphan list in journal writing process, which ensures that both xattr and dentry be effective in atomic when powercut happens.
Fixes: d7f0b70d30ff ("UBIFS: Add security.* XATTR support for the UBIFS") Fixes: d475a507457b ("ubifs: Add skeleton for fscrypto") Link: https://bugzilla.kernel.org/show_bug.cgi?id=218309 Suggested-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Conflicts: fs/ubifs/dir.c Signed-off-by: ZhaoLong Wang wangzhaolong1@huawei.com --- fs/ubifs/dir.c | 59 +++++++++++++++++++++++++++++++--------------- fs/ubifs/journal.c | 14 +++++++---- fs/ubifs/ubifs.h | 4 ++-- 3 files changed, 51 insertions(+), 26 deletions(-)
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 5b7e1d469a8b..67f4fe4deed1 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -71,8 +71,13 @@ static int inherit_flags(const struct inode *dir, umode_t mode) * @is_xattr: whether the inode is xattr inode * * This function finds an unused inode number, allocates new inode and - * initializes it. Returns new inode in case of success and an error code in - * case of failure. + * initializes it. Non-xattr new inode may be written with xattrs(selinux/ + * encryption) before writing dentry, which could cause inconsistent problem + * when powercut happens between two operations. To deal with it, non-xattr + * new inode is initialized with zero-nlink and added into orphan list, caller + * should make sure that inode is relinked later, and make sure that orphan + * removing and journal writing into an committing atomic operation. Returns + * new inode in case of success and an error code in case of failure. */ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, umode_t mode, bool is_xattr) @@ -164,9 +169,25 @@ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, ui->creat_sqnum = ++c->max_sqnum; spin_unlock(&c->cnt_lock);
+ if (!is_xattr) { + set_nlink(inode, 0); + err = ubifs_add_orphan(c, inode->i_ino); + if (err) { + ubifs_err(c, "ubifs_add_orphan failed: %i", err); + goto out_iput; + } + down_read(&c->commit_sem); + ui->del_cmtno = c->cmt_no; + up_read(&c->commit_sem); + } + if (encrypted) { err = fscrypt_set_context(inode, NULL); if (err) { + if (!is_xattr) { + set_nlink(inode, 1); + ubifs_delete_orphan(c, inode->i_ino); + } ubifs_err(c, "fscrypt_set_context failed: %i", err); goto out_iput; } @@ -321,11 +342,12 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, if (err) goto out_inode;
+ set_nlink(inode, 1); mutex_lock(&dir_ui->ui_mutex); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); @@ -340,8 +362,8 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); + set_nlink(inode, 0); out_inode: - make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); @@ -386,7 +408,6 @@ static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) return inode;
out_inode: - make_bad_inode(inode); iput(inode); out_free: ubifs_err(c, "cannot create whiteout file, error %d", err); @@ -469,6 +490,7 @@ static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry, if (err) goto out_inode;
+ set_nlink(inode, 1); mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); d_tmpfile(dentry, inode); @@ -478,7 +500,7 @@ static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry, mutex_unlock(&ui->ui_mutex);
lock_2_inodes(dir, inode); - err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 1); if (err) goto out_cancel; unlock_2_inodes(dir, inode); @@ -491,7 +513,6 @@ static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry, out_cancel: unlock_2_inodes(dir, inode); out_inode: - make_bad_inode(inode); if (!instantiated) iput(inode); out_budg: @@ -1006,6 +1027,7 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) if (err) goto out_inode;
+ set_nlink(inode, 1); mutex_lock(&dir_ui->ui_mutex); insert_inode_hash(inode); inc_nlink(inode); @@ -1013,7 +1035,7 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); if (err) { ubifs_err(c, "cannot create directory, error %d", err); goto out_cancel; @@ -1030,8 +1052,8 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) dir_ui->ui_size = dir->i_size; drop_nlink(dir); mutex_unlock(&dir_ui->ui_mutex); + set_nlink(inode, 0); out_inode: - make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); @@ -1101,12 +1123,13 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry, ui = ubifs_inode(inode); ui->data = dev; ui->data_len = devlen; + set_nlink(inode, 1);
mutex_lock(&dir_ui->ui_mutex); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); @@ -1121,8 +1144,8 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry, dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); + set_nlink(inode, 0); out_inode: - make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); @@ -1201,12 +1224,13 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, */ ui->data_len = disk_link.len - 1; inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1; + set_nlink(inode, 1);
mutex_lock(&dir_ui->ui_mutex); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 1); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); @@ -1220,10 +1244,10 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; mutex_unlock(&dir_ui->ui_mutex); + set_nlink(inode, 0); out_inode: /* Free inode->i_link before inode is marked as bad. */ fscrypt_free_inode(inode); - make_bad_inode(inode); iput(inode); out_fname: fscrypt_free_filename(&nm); @@ -1392,14 +1416,10 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, */ err = ubifs_budget_space(c, &wht_req); if (err) { - /* - * Whiteout inode can not be written on flash by - * ubifs_jnl_write_inode(), because it's neither - * dirty nor zero-nlink. - */ iput(whiteout); goto out_release; } + set_nlink(whiteout, 1);
/* Add the old_dentry size to the old_dir size. */ old_sz -= CALC_DENT_SIZE(fname_len(&old_nm)); @@ -1482,7 +1502,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, }
err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, - new_inode, &new_nm, whiteout, sync); + new_inode, &new_nm, whiteout, sync, !!whiteout); if (err) goto out_cancel;
@@ -1535,6 +1555,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); if (whiteout) { ubifs_release_budget(c, &wht_req); + set_nlink(whiteout, 0); iput(whiteout); } out_release: diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index dfbedbf0dc42..63b957c457d5 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -643,7 +643,7 @@ static void set_dent_cookie(struct ubifs_info *c, struct ubifs_dent_node *dent) * @inode: inode to update * @deletion: indicates a directory entry deletion i.e unlink or rmdir * @xent: non-zero if the directory entry is an extended attribute entry - * @delete_orphan: indicates an orphan entry deletion for @inode + * @in_orphan: indicates whether the @inode is in orphan list * * This function updates an inode by writing a directory entry (or extended * attribute entry), the inode itself, and the parent directory inode (or the @@ -665,7 +665,7 @@ static void set_dent_cookie(struct ubifs_info *c, struct ubifs_dent_node *dent) */ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, const struct fscrypt_name *nm, const struct inode *inode, - int deletion, int xent, int delete_orphan) + int deletion, int xent, int in_orphan) { int err, dlen, ilen, len, lnum, ino_offs, dent_offs, orphan_added = 0; int aligned_dlen, aligned_ilen, sync = IS_DIRSYNC(dir); @@ -751,7 +751,7 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, if (err) goto out_release;
- if (last_reference) { + if (last_reference && !in_orphan) { err = ubifs_add_orphan(c, inode->i_ino); if (err) { release_head(c, BASEHD); @@ -807,7 +807,7 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, if (err) goto out_ro;
- if (delete_orphan) + if (in_orphan && inode->i_nlink) ubifs_delete_orphan(c, inode->i_ino);
finish_reservation(c); @@ -1340,6 +1340,7 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, * @new_nm: new name of the new directory entry * @whiteout: whiteout inode * @sync: non-zero if the write-buffer has to be synchronized + * @delete_orphan: indicates an orphan entry deletion for @whiteout * * This function implements the re-name operation which may involve writing up * to 4 inodes(new inode, whiteout inode, old and new parent directory inodes) @@ -1352,7 +1353,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *new_dir, const struct inode *new_inode, const struct fscrypt_name *new_nm, - const struct inode *whiteout, int sync) + const struct inode *whiteout, int sync, int delete_orphan) { void *p; union ubifs_key key; @@ -1569,6 +1570,9 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, goto out_ro; }
+ if (delete_orphan) + ubifs_delete_orphan(c, whiteout->i_ino); + finish_reservation(c); if (new_inode) { mark_inode_clean(c, new_ui); diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 2b447d53b0bb..a6ed11b6e15d 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -1771,7 +1771,7 @@ int ubifs_consolidate_log(struct ubifs_info *c); /* journal.c */ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, const struct fscrypt_name *nm, const struct inode *inode, - int deletion, int xent, int delete_orphan); + int deletion, int xent, int in_orphan); int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, const union ubifs_key *key, const void *buf, int len); int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode); @@ -1788,7 +1788,7 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *new_dir, const struct inode *new_inode, const struct fscrypt_name *new_nm, - const struct inode *whiteout, int sync); + const struct inode *whiteout, int sync, int delete_orphan); int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode, loff_t old_size, loff_t new_size); int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,