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Commit | Line | Data |
---|---|---|
9d0aa67b GKH |
1 | From 6a3eb3360667170988f8a6477f6686242061488a Mon Sep 17 00:00:00 2001 |
2 | From: ZhangXiaoxu <zhangxiaoxu5@huawei.com> | |
3 | Date: Sat, 6 Apr 2019 15:47:38 +0800 | |
4 | Subject: cifs: Fix use-after-free in SMB2_write | |
5 | ||
6 | From: ZhangXiaoxu <zhangxiaoxu5@huawei.com> | |
7 | ||
8 | commit 6a3eb3360667170988f8a6477f6686242061488a upstream. | |
9 | ||
10 | There is a KASAN use-after-free: | |
11 | BUG: KASAN: use-after-free in SMB2_write+0x1342/0x1580 | |
12 | Read of size 8 at addr ffff8880b6a8e450 by task ln/4196 | |
13 | ||
14 | Should not release the 'req' because it will use in the trace. | |
15 | ||
16 | Fixes: eccb4422cf97 ("smb3: Add ftrace tracepoints for improved SMB3 debugging") | |
17 | ||
18 | Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com> | |
19 | Signed-off-by: Steve French <stfrench@microsoft.com> | |
20 | CC: Stable <stable@vger.kernel.org> 4.18+ | |
21 | Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> | |
22 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
23 | ||
24 | --- | |
25 | fs/cifs/smb2pdu.c | 2 +- | |
26 | 1 file changed, 1 insertion(+), 1 deletion(-) | |
27 | ||
28 | --- a/fs/cifs/smb2pdu.c | |
29 | +++ b/fs/cifs/smb2pdu.c | |
30 | @@ -3708,7 +3708,6 @@ SMB2_write(const unsigned int xid, struc | |
31 | ||
32 | rc = cifs_send_recv(xid, io_parms->tcon->ses, &rqst, | |
33 | &resp_buftype, flags, &rsp_iov); | |
34 | - cifs_small_buf_release(req); | |
35 | rsp = (struct smb2_write_rsp *)rsp_iov.iov_base; | |
36 | ||
37 | if (rc) { | |
38 | @@ -3726,6 +3725,7 @@ SMB2_write(const unsigned int xid, struc | |
39 | io_parms->offset, *nbytes); | |
40 | } | |
41 | ||
42 | + cifs_small_buf_release(req); | |
43 | free_rsp_buf(resp_buftype, rsp); | |
44 | return rc; | |
45 | } |