The patch titled Subject: nilfs2: fix infinite loop in nilfs_mdt_get_block() has been added to the -mm mm-hotfixes-unstable branch. Its filename is nilfs2-fix-infinite-loop-in-nilfs_mdt_get_block.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Ryusuke Konishi konishi.ryusuke@gmail.com Subject: nilfs2: fix infinite loop in nilfs_mdt_get_block() Date: Mon, 1 May 2023 04:30:46 +0900
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 ---
fs/nilfs2/bmap.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
--- a/fs/nilfs2/bmap.c~nilfs2-fix-infinite-loop-in-nilfs_mdt_get_block +++ a/fs/nilfs2/bmap.c @@ -67,20 +67,28 @@ 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 -mm which might be from konishi.ryusuke@gmail.com are
nilfs2-fix-infinite-loop-in-nilfs_mdt_get_block.patch