diff options
| author | Ryusuke Konishi <konishi.ryusuke@gmail.com> | 2024-07-25 14:20:07 +0900 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-07-26 14:33:10 -0700 |
| commit | 4811f7af6090e8f5a398fbdd766f903ef6c0d787 (patch) | |
| tree | 478c5830d16ca6933950a2f701abede62d88909e | |
| parent | f556acc2facdd240de2c7416cd1da48a1dae70ec (diff) | |
nilfs2: handle inconsistent state in nilfs_btnode_create_block()
Syzbot reported that a buffer state inconsistency was detected in
nilfs_btnode_create_block(), triggering a kernel bug.
It is not appropriate to treat this inconsistency as a bug; it can occur
if the argument block address (the buffer index of the newly created
block) is a virtual block number and has been reallocated due to
corruption of the bitmap used to manage its allocation state.
So, modify nilfs_btnode_create_block() and its callers to treat it as a
possible filesystem error, rather than triggering a kernel bug.
Link: https://lkml.kernel.org/r/20240725052007.4562-1-konishi.ryusuke@gmail.com
Fixes: a60be987d45d ("nilfs2: B-tree node cache")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+89cc4f2324ed37988b60@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=89cc4f2324ed37988b60
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/nilfs2/btnode.c | 25 | ||||
| -rw-r--r-- | fs/nilfs2/btree.c | 4 |
2 files changed, 22 insertions, 7 deletions
diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index 0131d83b912d..c034080c334b 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -51,12 +51,21 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node)); if (unlikely(!bh)) - return NULL; + return ERR_PTR(-ENOMEM); if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || buffer_dirty(bh))) { - brelse(bh); - BUG(); + /* + * The block buffer at the specified new address was already + * in use. This can happen if it is a virtual block number + * and has been reallocated due to corruption of the bitmap + * used to manage its allocation state (if not, the buffer + * clearing of an abandoned b-tree node is missing somewhere). + */ + nilfs_error(inode->i_sb, + "state inconsistency probably due to duplicate use of b-tree node block address %llu (ino=%lu)", + (unsigned long long)blocknr, inode->i_ino); + goto failed; } memset(bh->b_data, 0, i_blocksize(inode)); bh->b_bdev = inode->i_sb->s_bdev; @@ -67,6 +76,12 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) folio_unlock(bh->b_folio); folio_put(bh->b_folio); return bh; + +failed: + folio_unlock(bh->b_folio); + folio_put(bh->b_folio); + brelse(bh); + return ERR_PTR(-EIO); } int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, @@ -217,8 +232,8 @@ retry: } nbh = nilfs_btnode_create_block(btnc, newkey); - if (!nbh) - return -ENOMEM; + if (IS_ERR(nbh)) + return PTR_ERR(nbh); BUG_ON(nbh == obh); ctxt->newbh = nbh; diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index a139970e4804..862bdf23120e 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -63,8 +63,8 @@ static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree, struct buffer_head *bh; bh = nilfs_btnode_create_block(btnc, ptr); - if (!bh) - return -ENOMEM; + if (IS_ERR(bh)) + return PTR_ERR(bh); set_buffer_nilfs_volatile(bh); *bhp = bh; |