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authorRyusuke Konishi <konishi.ryusuke@gmail.com>2023-04-30 22:30:46 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-05-06 20:10:07 +0300
commita6a491c048882e7e424d407d32cba0b52d9ef2bf (patch)
treeb0e0138611cdaf9da4909b5a0c0f6df1ecf22e34
parent29417d292bd0fa174d20360326abaf6444a23c3b (diff)
downloadlinux-a6a491c048882e7e424d407d32cba0b52d9ef2bf.tar.xz
nilfs2: fix infinite loop in nilfs_mdt_get_block()
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@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+221d75710bde87fa0e97@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97 Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--fs/nilfs2/bmap.c16
1 files 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,