From: Theodore Ts'o tytso@mit.edu
commit b3e6bcb94590dea45396b9481e47b809b1be4afa upstream.
Add a new flag, EXT4_IGET_EA_INODE which indicates whether the inode is expected to have the EA_INODE flag or not. If the flag is not set/clear as expected, then fail the iget() operation and mark the file system as corrupted.
This commit also makes the ext4_iget() always perform the is_bad_inode() check even when the inode is already inode cache. This allows us to remove the is_bad_inode() check from the callers of ext4_iget() in the ea_inode code.
Reported-by: syzbot+cbb68193bdb95af4340a@syzkaller.appspotmail.com Reported-by: syzbot+62120febbd1ee3c3c860@syzkaller.appspotmail.com Reported-by: syzbot+edce54daffee36421b4c@syzkaller.appspotmail.com Cc: stable@kernel.org Signed-off-by: Theodore Ts'o tytso@mit.edu Link: https://lore.kernel.org/r/20230524034951.779531-2-tytso@mit.edu Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/ext4.h | 3 ++- fs/ext4/inode.c | 31 ++++++++++++++++++++++++++----- fs/ext4/xattr.c | 36 +++++++----------------------------- 3 files changed, 35 insertions(+), 35 deletions(-)
--- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2968,7 +2968,8 @@ typedef enum { EXT4_IGET_NORMAL = 0, EXT4_IGET_SPECIAL = 0x0001, /* OK to iget a system inode */ EXT4_IGET_HANDLE = 0x0002, /* Inode # is from a handle */ - EXT4_IGET_BAD = 0x0004 /* Allow to iget a bad inode */ + EXT4_IGET_BAD = 0x0004, /* Allow to iget a bad inode */ + EXT4_IGET_EA_INODE = 0x0008 /* Inode should contain an EA value */ } ext4_iget_flags;
extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4763,6 +4763,21 @@ static inline void ext4_inode_set_iversi inode_set_iversion_queried(inode, val); }
+static const char *check_igot_inode(struct inode *inode, ext4_iget_flags flags) + +{ + if (flags & EXT4_IGET_EA_INODE) { + if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) + return "missing EA_INODE flag"; + } else { + if ((EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) + return "unexpected EA_INODE flag"; + } + if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD)) + return "unexpected bad inode w/o EXT4_IGET_BAD"; + return NULL; +} + struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, ext4_iget_flags flags, const char *function, unsigned int line) @@ -4772,6 +4787,7 @@ struct inode *__ext4_iget(struct super_b struct ext4_inode_info *ei; struct ext4_super_block *es = EXT4_SB(sb)->s_es; struct inode *inode; + const char *err_str; journal_t *journal = EXT4_SB(sb)->s_journal; long ret; loff_t size; @@ -4799,8 +4815,14 @@ struct inode *__ext4_iget(struct super_b inode = iget_locked(sb, ino); if (!inode) return ERR_PTR(-ENOMEM); - if (!(inode->i_state & I_NEW)) + if (!(inode->i_state & I_NEW)) { + if ((err_str = check_igot_inode(inode, flags)) != NULL) { + ext4_error_inode(inode, function, line, 0, err_str); + iput(inode); + return ERR_PTR(-EFSCORRUPTED); + } return inode; + }
ei = EXT4_I(inode); iloc.bh = NULL; @@ -5066,10 +5088,9 @@ struct inode *__ext4_iget(struct super_b if (IS_CASEFOLDED(inode) && !ext4_has_feature_casefold(inode->i_sb)) ext4_error_inode(inode, function, line, 0, "casefold flag without casefold feature"); - if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD)) { - ext4_error_inode(inode, function, line, 0, - "bad inode without EXT4_IGET_BAD flag"); - ret = -EUCLEAN; + if ((err_str = check_igot_inode(inode, flags)) != NULL) { + ext4_error_inode(inode, function, line, 0, err_str); + ret = -EFSCORRUPTED; goto bad_inode; }
--- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -397,7 +397,7 @@ static int ext4_xattr_inode_iget(struct return -EFSCORRUPTED; }
- inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL); + inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_EA_INODE); if (IS_ERR(inode)) { err = PTR_ERR(inode); ext4_error(parent->i_sb, @@ -405,23 +405,6 @@ static int ext4_xattr_inode_iget(struct err); return err; } - - if (is_bad_inode(inode)) { - ext4_error(parent->i_sb, - "error while reading EA inode %lu is_bad_inode", - ea_ino); - err = -EIO; - goto error; - } - - if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { - ext4_error(parent->i_sb, - "EA inode %lu does not have EXT4_EA_INODE_FL flag", - ea_ino); - err = -EINVAL; - goto error; - } - ext4_xattr_inode_set_class(inode);
/* @@ -442,9 +425,6 @@ static int ext4_xattr_inode_iget(struct
*ea_inode = inode; return 0; -error: - iput(inode); - return err; }
/* Remove entry from mbcache when EA inode is getting evicted */ @@ -1507,11 +1487,10 @@ ext4_xattr_inode_cache_find(struct inode
while (ce) { ea_inode = ext4_iget(inode->i_sb, ce->e_value, - EXT4_IGET_NORMAL); - if (!IS_ERR(ea_inode) && - !is_bad_inode(ea_inode) && - (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) && - i_size_read(ea_inode) == value_len && + EXT4_IGET_EA_INODE); + if (IS_ERR(ea_inode)) + goto next_entry; + if (i_size_read(ea_inode) == value_len && !ext4_xattr_inode_read(ea_inode, ea_data, value_len) && !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data, value_len) && @@ -1521,9 +1500,8 @@ ext4_xattr_inode_cache_find(struct inode kvfree(ea_data); return ea_inode; } - - if (!IS_ERR(ea_inode)) - iput(ea_inode); + iput(ea_inode); + next_entry: ce = mb_cache_entry_find_next(ea_inode_cache, ce); } kvfree(ea_data);