This is a note to let you know that I've just added the patch titled
nilfs2: fix infinite loop in nilfs_mdt_get_block()
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nilfs2-fix-infinite-loop-in-nilfs_mdt_get_block.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a6a491c048882e7e424d407d32cba0b52d9ef2bf Mon Sep 17 00:00:00 2001
From: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Date: Mon, 1 May 2023 04:30:46 +0900
Subject: nilfs2: fix infinite loop in nilfs_mdt_get_block()
From: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
commit a6a491c048882e7e424d407d32cba0b52d9ef2bf upstream.
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.
Link: https://lkml.kernel.org/r/20230430193046.6769-1-konishi.ryusuke@xxxxxxxxx
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Tested-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Reported-by: syzbot+221d75710bde87fa0e97@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nilfs2/bmap.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -76,20 +76,28 @@ int nilfs_bmap_lookup_at_level(struct ni
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,
Patches currently in stable-queue which might be from konishi.ryusuke@xxxxxxxxx are
queue-4.14/nilfs2-do-not-write-dirty-data-after-degenerating-to-read-only.patch
queue-4.14/nilfs2-fix-infinite-loop-in-nilfs_mdt_get_block.patch
