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From: Sasha Levin <Alexander.Levin@microsoft.com>
To: "stable@vger.kernel.org" <stable@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
	Steven French <Steven.French@microsoft.com>,
	Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL 3.18 11/13] cifs: read overflow in is_valid_oplock_break()
Date: Mon, 1 Oct 2018 00:41:52 +0000	[thread overview]
Message-ID: <20181001004139.147341-11-alexander.levin@microsoft.com> (raw)
In-Reply-To: <20181001004139.147341-1-alexander.levin@microsoft.com>

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 097f5863b1a0c9901f180bbd56ae7d630655faaa ]

We need to verify that the "data_offset" is within bounds.

Reported-by: Dr Silvio Cesare of InfoSect <silvio.cesare@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 fs/cifs/misc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index eedbc34e19db..c8662e212afc 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -405,9 +405,17 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
 			(struct smb_com_transaction_change_notify_rsp *)buf;
 		struct file_notify_information *pnotify;
 		__u32 data_offset = 0;
+		size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
+
 		if (get_bcc(buf) > sizeof(struct file_notify_information)) {
 			data_offset = le32_to_cpu(pSMBr->DataOffset);
 
+			if (data_offset >
+			    len - sizeof(struct file_notify_information)) {
+				cifs_dbg(FYI, "invalid data_offset %u\n",
+					 data_offset);
+				return true;
+			}
 			pnotify = (struct file_notify_information *)
 				((char *)&pSMBr->hdr.Protocol + data_offset);
 			cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
-- 
2.17.1

  parent reply	other threads:[~2018-10-01  0:41 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-01  0:41 [PATCH AUTOSEL 3.18 01/13] usb: gadget: fotg210-udc: Fix memory leak of fotg210->ep[i] Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 02/13] pinctrl: msm: Really mask level interrupts to prevent latching Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 03/13] RDMA/ucma: check fd type in ucma_migrate_id() Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 04/13] USB: yurex: Check for truncation in yurex_read() Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 05/13] fs/cifs: suppress a string overflow warning Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 06/13] dm thin metadata: try to avoid ever aborting transactions Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 07/13] arch/hexagon: fix kernel/dma.c build warning Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 08/13] hexagon: modify ffs() and fls() to return int Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 09/13] r8169: Clear RTL_FLAG_TASK_*_PENDING when clearing RTL_FLAG_TASK_ENABLED Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 10/13] s390/qeth: don't dump past end of unknown HW header Sasha Levin
2018-10-01  0:41 ` Sasha Levin [this message]
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 12/13] xen/manage: don't complain about an empty value in control/sysrq node Sasha Levin
2018-10-01  0:41 ` [PATCH AUTOSEL 3.18 13/13] xen: fix GCC warning and remove duplicate EVTCHN_ROW/EVTCHN_COL usage Sasha Levin

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