From a3dc607a9dd73082eefe0dab3d43cd093ce77462 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 28 Mar 2019 10:41:06 +0800 Subject: [PATCH] ext4: prohibit fstrim in norecovery mode mainline inclusion from mainline-5.1-rc2 commit 18915b5873f07e5030e6fb108a050fa7c71c59fb category: bugfix bugzilla: 13105 CVE: NA ------------------------------------------------- The ext4 fstrim implementation uses the block bitmaps to find free space that can be discarded. If we haven't replayed the journal, the bitmaps will be stale and we absolutely *cannot* use stale metadata to zap the underlying storage. Signed-off-by: Darrick J. Wong Signed-off-by: Theodore Ts'o Signed-off-by: luojiajun Reviewed-by: yangerkun Signed-off-by: Yang Yingliang --- fs/ext4/ioctl.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 80bee0bfbc9f..d79cf63d9c0f 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1004,6 +1004,13 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (!blk_queue_discard(q)) return -EOPNOTSUPP; + /* + * We haven't replayed the journal, so we cannot use our + * block-bitmap-guided storage zapping commands. + */ + if (test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) + return -EROFS; + if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range))) return -EFAULT; -- GitLab