From: Ryusuke Konishi <konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Cc: linux-nilfs <linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
syzbot
<syzbot+221d75710bde87fa0e97-Pl5Pbv+GP7P466ipTTIvnc23WoclnBCfAL8bYrjMMd8@public.gmane.org>,
syzkaller-bugs-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org,
LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-fsdevel
<linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: [PATCH] nilfs2: fix infinite loop in nilfs_mdt_get_block()
Date: Mon, 1 May 2023 04:30:46 +0900 [thread overview]
Message-ID: <20230430193046.6769-1-konishi.ryusuke@gmail.com> (raw)
In-Reply-To: <CAKFNMonK2VcZx=KEG8cz61bhwMvChEJ=T+FecxpGg1QiRCcZhA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
If the disk image that nilfs2 mounts is corrupted and a virtual block
address obtained by block lookup for a metadata file is invalid,
nilfs_bmap_lookup_at_level() may return the same internal return code
as -ENOENT, meaning the block does not exist in the metadata file.
This duplication of return codes confuses nilfs_mdt_get_block(), causing
it to read and create a metadata block indefinitely.
In particular, if this happens to the inode metadata file, ifile,
semaphore i_rwsem can be left held, causing task hangs in lock_mount.
Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual
block address translation failures with -ENOENT as metadata corruption
instead of returning the error code.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Reported-by: syzbot+221d75710bde87fa0e97-Pl5Pbv+GP7P466ipTTIvnc23WoclnBCfAL8bYrjMMd8@public.gmane.org
Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97
Tested-by: Ryusuke Konishi <konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
fs/nilfs2/bmap.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index 798a2c1b38c6..7a8f166f2c8d 100644
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -67,20 +67,28 @@ int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
down_read(&bmap->b_sem);
ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
- if (ret < 0) {
- ret = nilfs_bmap_convert_error(bmap, __func__, ret);
+ if (ret < 0)
goto out;
- }
+
if (NILFS_BMAP_USE_VBN(bmap)) {
ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
&blocknr);
if (!ret)
*ptrp = blocknr;
+ else if (ret == -ENOENT) {
+ /*
+ * If there was no valid entry in DAT for the block
+ * address obtained by b_ops->bop_lookup, then pass
+ * internal code -EINVAL to nilfs_bmap_convert_error
+ * to treat it as metadata corruption.
+ */
+ ret = -EINVAL;
+ }
}
out:
up_read(&bmap->b_sem);
- return ret;
+ return nilfs_bmap_convert_error(bmap, __func__, ret);
}
int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
--
2.34.1
parent reply other threads:[~2023-04-30 19:30 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <CAKFNMonK2VcZx=KEG8cz61bhwMvChEJ=T+FecxpGg1QiRCcZhA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230430193046.6769-1-konishi.ryusuke@gmail.com \
--to=konishi.ryusuke-re5jqeeqqe8avxtiumwx3w@public.gmane.org \
--cc=akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org \
--cc=linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=syzbot+221d75710bde87fa0e97-Pl5Pbv+GP7P466ipTTIvnc23WoclnBCfAL8bYrjMMd8@public.gmane.org \
--cc=syzkaller-bugs-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).