linux-ext4 - [PATCH v2] ext4: fix bug for rename with RENAME

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 29 Dec 2020 17:02:08 +0800
From:   yangerkun <yangerkun@...wei.com>
To:     <linux-ext4@...r.kernel.org>, <tytso@....edu>,
        <adilger.kernel@...ger.ca>, <jack@...e.cz>
CC:     <yi.zhang@...wei.com>, <lihaotian9@...wei.com>,
        <lutianxiong@...wei.com>, <linfeilong@...wei.com>,
        <yangerkun@...wei.com>
Subject: [PATCH v2] ext4: fix bug for rename with RENAME_WHITEOUT

ext4_rename will create a special inode for whiteout and use this 'ino'
to replace the source file's dir entry 'ino'. Once error happens
latter(small ext4 img, and consume all space, so the rename with dst
path not exist will fail due to the ENOSPC return from ext4_add_entry in
ext4_rename), the cleanup do drop the nlink for whiteout, but forget to
restore 'ino' with source file. This will lead to "deleted inode
referenced".

Signed-off-by: yangerkun <yangerkun@...wei.com>
---
 fs/ext4/namei.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index b17a082b7db1..b3acfd384583 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3593,9 +3593,6 @@ static int ext4_setent(handle_t *handle, struct ext4_renament *ent,
 			return retval2;
 		}
 	}
-	brelse(ent->bh);
-	ent->bh = NULL;
-
 	return retval;
 }
 
@@ -3794,6 +3791,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		}
 	}
 
+	old_file_type = old.de->file_type;
 	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
 		ext4_handle_sync(handle);
 
@@ -3821,7 +3819,6 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 	force_reread = (new.dir->i_ino == old.dir->i_ino &&
 			ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
 
-	old_file_type = old.de->file_type;
 	if (whiteout) {
 		/*
 		 * Do this before adding a new entry, so the old entry is sure
@@ -3919,15 +3916,17 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 	retval = 0;
 
 end_rename:
-	brelse(old.dir_bh);
-	brelse(old.bh);
-	brelse(new.bh);
 	if (whiteout) {
+		ext4_setent(handle, &old,
+			    old.inode->i_ino, old_file_type);
 		if (retval)
 			drop_nlink(whiteout);
 		unlock_new_inode(whiteout);
 		iput(whiteout);
 	}
+	brelse(old.dir_bh);
+	brelse(old.bh);
+	brelse(new.bh);
 	if (handle)
 		ext4_journal_stop(handle);
 	return retval;
-- 
2.25.4