When trying to mount a file system which does not contain a journal, but which does have a orphan list with an inode which needs to be truncated, the mount call with hang forever in ext4_orphan_cleanup() because ext4_orphan_del() will return immediately if no journal is present.
This can be trivially reproduced by trying to mount the file system found in tests/f_orphan_extents_inode/image.gz in the e2fsprogs sources. If a malicious user were to put this on a USB stick, and mount it on a Linux desktop which automatically mounts newly inserted USB sticks, this could be considered a potential denial of service attack. (Not a big deal in practice, but professional paranoids worry about such things, and have even been known to allocate CVE numbers on occasion.) Signed-off-by: "Theodore Ts'o" <[email protected]> Cc: [email protected] --- fs/ext4/namei.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index cac4482..8990165 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2648,7 +2648,8 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) struct ext4_iloc iloc; int err = 0; - if (!EXT4_SB(inode->i_sb)->s_journal) + if ((!EXT4_SB(inode->i_sb)->s_journal) && + !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) return 0; mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); -- 1.7.12.rc0.22.gcdd159b -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
