From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3ABBEC8CD for ; Mon, 19 Jun 2023 10:59:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3BD7C433C8; Mon, 19 Jun 2023 10:59:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687172356; bh=t6BM1ispRrrUdWx8WNvPLixKSPnfmDzRY+ZEq6s6z9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=glOIyHoU+0YYaPNK17bQ8POG0pIgjlG60mp+13EnPkuWxn/yKzRD6i8nygqePk3jd BxFrhwx5Si5Sc1w+3spiA1/60/8KArgBZH364UikIzec79QurcW+1VZbADLIK2BTQ6 oJCA7wzwRS14FZ+jMSAykJqbfGgM7tp8cBN5prD8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , syzbot+b0a35a5c1f7e846d3b09@syzkaller.appspotmail.com, Andrew Morton Subject: [PATCH 5.15 039/107] nilfs2: fix incomplete buffer cleanup in nilfs_btnode_abort_change_key() Date: Mon, 19 Jun 2023 12:30:23 +0200 Message-ID: <20230619102143.382429029@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230619102141.541044823@linuxfoundation.org> References: <20230619102141.541044823@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ryusuke Konishi commit 2f012f2baca140c488e43d27a374029c1e59098d upstream. A syzbot fault injection test reported that nilfs_btnode_create_block, a helper function that allocates a new node block for b-trees, causes a kernel BUG for disk images where the file system block size is smaller than the page size. This was due to unexpected flags on the newly allocated buffer head, and it turned out to be because the buffer flags were not cleared by nilfs_btnode_abort_change_key() after an error occurred during a b-tree update operation and the buffer was later reused in that state. Fix this issue by using nilfs_btnode_delete() to abandon the unused preallocated buffer in nilfs_btnode_abort_change_key(). Link: https://lkml.kernel.org/r/20230513102428.10223-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+b0a35a5c1f7e846d3b09@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000d1d6c205ebc4d512@google.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/btnode.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -285,6 +285,14 @@ void nilfs_btnode_abort_change_key(struc if (nbh == NULL) { /* blocksize == pagesize */ xa_erase_irq(&btnc->i_pages, newkey); unlock_page(ctxt->bh->b_page); - } else - brelse(nbh); + } else { + /* + * When canceling a buffer that a prepare operation has + * allocated to copy a node block to another location, use + * nilfs_btnode_delete() to initialize and release the buffer + * so that the buffer flags will not be in an inconsistent + * state when it is reallocated. + */ + nilfs_btnode_delete(nbh); + } }