From nobody Sun Feb 8 15:59:15 2026 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 66DF3C7EE2E for ; Sat, 27 May 2023 01:42:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231478AbjE0BmE (ORCPT ); Fri, 26 May 2023 21:42:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230414AbjE0BmB (ORCPT ); Fri, 26 May 2023 21:42:01 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F160AF3 for ; Fri, 26 May 2023 18:41:58 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.54]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QSktX5hpMz18Ldx; Sat, 27 May 2023 09:37:24 +0800 (CST) Received: from huawei.com (10.175.127.227) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Sat, 27 May 2023 09:41:57 +0800 From: Ye Bin To: , CC: , Subject: [PATCH 1/2] quota: fix null-ptr-deref in ext4_acquire_dquot() Date: Sat, 27 May 2023 09:40:17 +0800 Message-ID: <20230527014018.47396-2-yebin10@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230527014018.47396-1-yebin10@huawei.com> References: <20230527014018.47396-1-yebin10@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Syzbot found the following issue: Unable to handle kernel paging request at virtual address dfff800000000005 KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] Mem abort info: ESR =3D 0x0000000096000006 EC =3D 0x25: DABT (current EL), IL =3D 32 bits SET =3D 0, FnV =3D 0 EA =3D 0, S1PTW =3D 0 FSC =3D 0x06: level 2 translation fault Data abort info: ISV =3D 0, ISS =3D 0x00000006 CM =3D 0, WnR =3D 0 [dfff800000000005] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 6080 Comm: syz-executor747 Not tainted 6.3.0-rc7-syzkaller-g14f= 8db1c0f9a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 04/14/2023 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=3D--) pc : ext4_acquire_dquot+0x1d4/0x398 fs/ext4/super.c:6766 lr : dquot_to_inode fs/ext4/super.c:6740 [inline] lr : ext4_acquire_dquot+0x1ac/0x398 fs/ext4/super.c:6766 sp : ffff80001eb27280 x29: ffff80001eb27280 x28: 1fffe0001c3c01fc x27: ffff800015d705b0 x26: ffff0000dd93c000 x25: ffff0000dd93e000 x24: 1fffe0001c3c021c x23: dfff800000000000 x22: 0000000000000049 x21: 0000000000000028 x20: 0000000000000000 x19: ffff0000e1e00fc0 x18: ffff0001b426cca8 x17: 0000000000000000 x16: ffff8000089669b0 x15: 0000000000000001 x14: 1ffff00002bae0b0 x13: dfff800000000000 x12: 0000000000000001 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000005 x7 : ffff800008c11f68 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800012441b4c x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000003 Call trace: ext4_acquire_dquot+0x1d4/0x398 fs/ext4/super.c:6766 dqget+0x844/0xc48 fs/quota/dquot.c:914 __dquot_initialize+0x2cc/0xb54 fs/quota/dquot.c:1492 dquot_initialize fs/quota/dquot.c:1550 [inline] dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2181 ext4_file_open+0x230/0x590 fs/ext4/file.c:903 do_dentry_open+0x724/0xf90 fs/open.c:920 vfs_open+0x7c/0x90 fs/open.c:1051 do_open fs/namei.c:3560 [inline] path_openat+0x1f2c/0x27f8 fs/namei.c:3715 do_filp_open+0x1bc/0x3cc fs/namei.c:3742 do_sys_openat2+0x128/0x3d8 fs/open.c:1348 do_sys_open fs/open.c:1364 [inline] __do_sys_openat fs/open.c:1380 [inline] __se_sys_openat fs/open.c:1375 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1375 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193 el0_svc+0x4c/0x15c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591 Code: 97e8a7df f94002a8 9100a115 d343fea8 (38776908) Reported-by: syzbot+e633c79ceaecbf479854@syzkaller.appspotmail.com ---[ end trace 0000000000000000 ]--- Above issue may happens as follows: ProcessA ProcessB ProcessC sys_fsconfig vfs_fsconfig_locked reconfigure_super ext4_remount dquot_suspend -> suspend all type quota sys_fsconfig vfs_fsconfig_locked reconfigure_super ext4_remount dquot_resume ret =3D dquot_load_quota_sb add_dquot_ref do_open -> open file O_RDWR vfs_open do_dentry_open get_write_access atomic_inc_unless_negative(&inode->i_writecount) ext4_file_open dquot_file_open dquot_initialize __dquot_initialize dqget if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) __dquot_initialize __dquot_initialize dqget if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) ext4_acquire_dquot -> Return error if (ret < 0) vfs_cleanup_quota_inode dqopt->files[type] =3D NULL; ext4_acquire_dquot -->dquot_to_inode(dquot) is NULL To solve above issue, if quota has been loaded, there's unneed to cleaup qu= ota inode if dquot_load_quota_sb() return failed when do dquot_resume(); Reported-by: syzbot+e633c79ceaecbf479854@syzkaller.appspotmail.com Signed-off-by: Ye Bin --- fs/quota/dquot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index ffd40dc3e4e9..4b913faa48ec 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2476,7 +2476,7 @@ int dquot_resume(struct super_block *sb, int type) flags =3D dquot_generic_flag(flags, cnt); ret =3D dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, flags); - if (ret < 0) + if (ret < 0 && !sb_has_quota_loaded(sb, cnt)) vfs_cleanup_quota_inode(sb, cnt); } =20 --=20 2.31.1