From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 127D8C4332F for ; Sat, 17 Dec 2022 15:27:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229793AbiLQP1m (ORCPT ); Sat, 17 Dec 2022 10:27:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229471AbiLQP1g (ORCPT ); Sat, 17 Dec 2022 10:27:36 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ECDB1209F; Sat, 17 Dec 2022 07:27:35 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id EA640B802C7; Sat, 17 Dec 2022 15:27:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBEBFC43396; Sat, 17 Dec 2022 15:27:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671290852; bh=I/zdy7+QKG3Cv90hZDVxJEpjwhTDKPv0eyifLuuWcG8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fv6CENzGd61fCkAgq5zmF2HZwEjYBJgOkMuWUtvOcEUvpIFtZCKfTNkXi4J51EQoF 7QBxAYInWqH9LBAUFv7ORR9xA1SCcsRRevb8yJ5Ngx8PBCB2zS6vL/aZLUDX4e3BdI UxXPXHvsOg8O5B54a1BMkOZmce9vU1xlgtB2KlxzBAb+koT0zv3aVh5O11SbvAwLBc SsmGJ+BtNGkx2a51GPKfsHGOzrjYxbCJ5Wv1BG/fR9uD5rm3/chekaeuO41wbkEkdm S3DlgiV3nxQKvcAYIWpDqciGHxmrAmPtYSZzCOTFqO5bhf34VX4APnaVn5vbVx7oo3 o9lrGPoGTrrkQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Shigeru Yoshida , syzbot+7902cd7684bc35306224@syzkaller.appspotmail.com, Jan Kara , Sasha Levin , jack@suse.com Subject: [PATCH AUTOSEL 6.1 02/22] udf: Avoid double brelse() in udf_rename() Date: Sat, 17 Dec 2022 10:27:03 -0500 Message-Id: <20221217152727.98061-2-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221217152727.98061-1-sashal@kernel.org> References: <20221217152727.98061-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shigeru Yoshida [ Upstream commit c791730f2554a9ebb8f18df9368dc27d4ebc38c2 ] syzbot reported a warning like below [1]: VFS: brelse: Trying to free free buffer WARNING: CPU: 2 PID: 7301 at fs/buffer.c:1145 __brelse+0x67/0xa0 ... Call Trace: invalidate_bh_lru+0x99/0x150 smp_call_function_many_cond+0xe2a/0x10c0 ? generic_remap_file_range_prep+0x50/0x50 ? __brelse+0xa0/0xa0 ? __mutex_lock+0x21c/0x12d0 ? smp_call_on_cpu+0x250/0x250 ? rcu_read_lock_sched_held+0xb/0x60 ? lock_release+0x587/0x810 ? __brelse+0xa0/0xa0 ? generic_remap_file_range_prep+0x50/0x50 on_each_cpu_cond_mask+0x3c/0x80 blkdev_flush_mapping+0x13a/0x2f0 blkdev_put_whole+0xd3/0xf0 blkdev_put+0x222/0x760 deactivate_locked_super+0x96/0x160 deactivate_super+0xda/0x100 cleanup_mnt+0x222/0x3d0 task_work_run+0x149/0x240 ? task_work_cancel+0x30/0x30 do_exit+0xb29/0x2a40 ? reacquire_held_locks+0x4a0/0x4a0 ? do_raw_spin_lock+0x12a/0x2b0 ? mm_update_next_owner+0x7c0/0x7c0 ? rwlock_bug.part.0+0x90/0x90 ? zap_other_threads+0x234/0x2d0 do_group_exit+0xd0/0x2a0 __x64_sys_exit_group+0x3a/0x50 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd The cause of the issue is that brelse() is called on both ofibh.sbh and ofibh.ebh by udf_find_entry() when it returns NULL. However, brelse() is called by udf_rename(), too. So, b_count on buffer_head becomes unbalanced. This patch fixes the issue by not calling brelse() by udf_rename() when udf_find_entry() returns NULL. Link: https://syzkaller.appspot.com/bug?id=8297f45698159c6bca8a1f87dc983667c1a1c851 [1] Reported-by: syzbot+7902cd7684bc35306224@syzkaller.appspotmail.com Signed-off-by: Shigeru Yoshida Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20221023095741.271430-1-syoshida@redhat.com Signed-off-by: Sasha Levin --- fs/udf/namei.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/udf/namei.c b/fs/udf/namei.c index ae7bc13a5298..7c95c549dd64 100644 --- a/fs/udf/namei.c +++ b/fs/udf/namei.c @@ -1091,8 +1091,9 @@ static int udf_rename(struct user_namespace *mnt_userns, struct inode *old_dir, return -EINVAL; ofi = udf_find_entry(old_dir, &old_dentry->d_name, &ofibh, &ocfi); - if (IS_ERR(ofi)) { - retval = PTR_ERR(ofi); + if (!ofi || IS_ERR(ofi)) { + if (IS_ERR(ofi)) + retval = PTR_ERR(ofi); goto end_rename; } @@ -1101,8 +1102,7 @@ static int udf_rename(struct user_namespace *mnt_userns, struct inode *old_dir, brelse(ofibh.sbh); tloc = lelb_to_cpu(ocfi.icb.extLocation); - if (!ofi || udf_get_lb_pblock(old_dir->i_sb, &tloc, 0) - != old_inode->i_ino) + if (udf_get_lb_pblock(old_dir->i_sb, &tloc, 0) != old_inode->i_ino) goto end_rename; nfi = udf_find_entry(new_dir, &new_dentry->d_name, &nfibh, &ncfi); -- 2.35.1