From b3e6bcb94590dea45396b9481e47b809b1be4afa Mon Sep 17 00:00:00 2001
From: Theodore Ts'o <tytso@mit.edu>
Date: Tue, 23 May 2023 23:49:48 -0400
Subject: [PATCH] ext4: add EA_INODE checking to ext4_iget()
Git-commit: b3e6bcb94590dea45396b9481e47b809b1be4afa
Patch-mainline: v6.4-rc5
References: bsc#1213106
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
Acked-by: Jan Kara <jack@suse.cz>
---
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
@@ -2976,7 +2976,8 @@ 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
@@ -4635,6 +4635,21 @@ static inline u64 ext4_inode_peek_iversi
return inode_peek_iversion(inode);
}
+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)
@@ -4643,6 +4658,7 @@ struct inode *__ext4_iget(struct super_b
struct ext4_inode *raw_inode;
struct ext4_inode_info *ei;
struct inode *inode;
+ const char *err_str;
journal_t *journal = EXT4_SB(sb)->s_journal;
long ret;
loff_t size;
@@ -4666,8 +4682,14 @@ 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;
@@ -4936,10 +4958,9 @@ 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);