From nobody Sun May 10 06:27:48 2026 Received: from mx0b-0064b401.pphosted.com (mx0b-0064b401.pphosted.com [205.220.178.238]) (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 689F312CD88 for ; Mon, 30 Dec 2024 06:09:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.178.238 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735538989; cv=none; b=SmqiCuwmQX8dadDI8PxwrxI5DP19jo6loqpDTaItq8C7Ji5/HC+w5TyluYIJyx+vRRsAPywtcpr7K7c+kFYvB0X0RRAum/Xc0SFbde7oWTP4kyrWr3KLxgqDJxIoehrkgAGZWdaN0uW+1/DVLWGUBPf/yZOCL1nkXUkdb+HDbWw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735538989; c=relaxed/simple; bh=7AsGo/0t6TAVCFCltE/hfFmlgI59Ofa/NWUaLvBkJ7g=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Wpu0pglcaLtb3DWYk6o/IyZ67vcykGFT6oVYp3tn4JSwp7gR4YUa7v+8KnGODnWoLsX2FrrlozT9h/IoNOIaxFu36Uobd3gZKeVLcPLN4IpEfQMBhMi7yZfAUZfI6DsjbH6ejE3Kym7f2LIdDSADxGr0o2dOcTjgXWFNUit90DQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com; spf=pass smtp.mailfrom=windriver.com; arc=none smtp.client-ip=205.220.178.238 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=windriver.com Received: from pps.filterd (m0250811.ppops.net [127.0.0.1]) by mx0a-0064b401.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4BU5UVfG018907; Mon, 30 Dec 2024 06:09:07 GMT Received: from ala-exchng01.corp.ad.wrs.com (ala-exchng01.wrs.com [147.11.82.252]) by mx0a-0064b401.pphosted.com (PPS) with ESMTPS id 43t6j0he48-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Mon, 30 Dec 2024 06:09:06 +0000 (GMT) Received: from ALA-EXCHNG02.corp.ad.wrs.com (147.11.82.254) by ala-exchng01.corp.ad.wrs.com (147.11.82.252) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.43; Sun, 29 Dec 2024 22:09:05 -0800 Received: from pek-lpd-ccm6.wrs.com (147.11.136.210) by ALA-EXCHNG02.corp.ad.wrs.com (147.11.82.254) with Microsoft SMTP Server id 15.1.2507.43 via Frontend Transport; Sun, 29 Dec 2024 22:09:03 -0800 From: Lizhi Xu To: CC: , , , Subject: [PATCH] fs/ntfs3: Keep write operations atomic Date: Mon, 30 Dec 2024 14:09:02 +0800 Message-ID: <20241230060902.7526-1-lizhi.xu@windriver.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <6771ebf2.050a0220.226966.00cb.GAE@google.com> References: <6771ebf2.050a0220.226966.00cb.GAE@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Authority-Analysis: v=2.4 cv=V7KH0fni c=1 sm=1 tr=0 ts=67723902 cx=c_pps a=/ZJR302f846pc/tyiSlYyQ==:117 a=/ZJR302f846pc/tyiSlYyQ==:17 a=RZcAm9yDv7YA:10 a=edf1wS77AAAA:8 a=hSkVLCK3AAAA:8 a=t7CeM3EgAAAA:8 a=drM_RmuUk77qzieWX1cA:9 a=DcSpbTIhAlouE1Uv7lRv:22 a=cQPPKAXgyycSBL8etih5:22 a=FdTzh2GWekK77mhwV6Dw:22 X-Proofpoint-ORIG-GUID: 5q_ZP9pp4u0wlW6I3EA4M7nSd99eeZ7c X-Proofpoint-GUID: 5q_ZP9pp4u0wlW6I3EA4M7nSd99eeZ7c X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2024-12-30_02,2024-12-24_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 mlxlogscore=943 priorityscore=1501 malwarescore=0 bulkscore=0 phishscore=0 clxscore=1011 impostorscore=0 adultscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam authscore=0 adjust=0 reason=mlx scancount=1 engine=8.21.0-2411120000 definitions=main-2412300050 Content-Type: text/plain; charset="utf-8" syzbot reported a NULL pointer dereference in __generic_file_write_iter. [1] Before the write operation is completed, the user executes ioctl[2] to clear the compress flag of the file, which causes the is_compressed() judgment to return 0, further causing the program to enter the wrong process and call t= he wrong ops ntfs_aops_cmpr, which triggers the null pointer dereference of write_begin. Use inode lock to synchronize ioctl and write to avoid this case. [1] Unable to handle kernel NULL pointer dereference at virtual address 0000000= 000000000 Mem abort info: ESR =3D 0x0000000086000006 EC =3D 0x21: IABT (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 user pgtable: 4k pages, 48-bit VAs, pgdp=3D000000011896d000 [0000000000000000] pgd=3D0800000118b44403, p4d=3D0800000118b44403, pud=3D08= 00000117517403, pmd=3D0000000000000000 Internal error: Oops: 0000000086000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 6427 Comm: syz-executor347 Not tainted 6.13.0-rc3-syzkal= ler-g573067a5a685 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 09/13/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=3D--) pc : 0x0 lr : generic_perform_write+0x29c/0x868 mm/filemap.c:4055 sp : ffff80009d4978a0 x29: ffff80009d4979c0 x28: dfff800000000000 x27: ffff80009d497bc8 x26: 0000000000000000 x25: ffff80009d497960 x24: ffff80008ba71c68 x23: 0000000000000000 x22: ffff0000c655dac0 x21: 0000000000001000 x20: 000000000000000c x19: 1ffff00013a92f2c x18: ffff0000e183aa1c x17: 0004060000000014 x16: ffff800083275834 x15: 0000000000000001 x14: 0000000000000000 x13: 0000000000000001 x12: ffff0000c655dac0 x11: 0000000000ff0100 x10: 0000000000ff0100 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : ffff80009d497980 x4 : ffff80009d497960 x3 : 0000000000001000 x2 : 0000000000000000 x1 : ffff0000e183a928 x0 : ffff0000d60b0fc0 Call trace: 0x0 (P) __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4156 ntfs_file_write_iter+0x54c/0x630 fs/ntfs3/file.c:1267 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x920/0xcf4 fs/read_write.c:679 ksys_write+0x15c/0x26c fs/read_write.c:731 __do_sys_write fs/read_write.c:742 [inline] __se_sys_write fs/read_write.c:739 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:739 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 [2] ioctl$FS_IOC_SETFLAGS(r0, 0x40086602, &(0x7f00000000c0)=3D0x20) Reported-by: syzbot+5d0bdc98770e6c55a0fd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3D5d0bdc98770e6c55a0fd Signed-off-by: Lizhi Xu --- fs/ntfs3/file.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c index 3f96a11804c9..ec6103c97321 100644 --- a/fs/ntfs3/file.c +++ b/fs/ntfs3/file.c @@ -1228,6 +1228,12 @@ static ssize_t ntfs_file_write_iter(struct kiocb *io= cb, struct iov_iter *from) ssize_t ret; int err; =20 + if (!inode_trylock(inode)) { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + inode_lock(inode); + } + err =3D check_write_restriction(inode); if (err) return err; @@ -1237,12 +1243,6 @@ static ssize_t ntfs_file_write_iter(struct kiocb *io= cb, struct iov_iter *from) return -EOPNOTSUPP; } =20 - if (!inode_trylock(inode)) { - if (iocb->ki_flags & IOCB_NOWAIT) - return -EAGAIN; - inode_lock(inode); - } - ret =3D generic_write_checks(iocb, from); if (ret <=3D 0) goto out; --=20 2.43.0