Commit 6a3eb336 authored Apr 06, 2019 by ZhangXiaoxu Committed by Steve French Apr 16, 2019

cifs: Fix use-after-free in SMB2_write



There is a KASAN use-after-free:
BUG: KASAN: use-after-free in SMB2_write+0x1342/0x1580
Read of size 8 at addr ffff8880b6a8e450 by task ln/4196

Should not release the 'req' because it will use in the trace.

Fixes: eccb4422 ("smb3: Add ftrace tracepoints for improved SMB3 debugging")

Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> 4.18+
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

parent 618d919c

fs/cifs/smb2pdu.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3769,7 +3769,6 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,

		rc = cifs_send_recv(xid, io_parms->tcon->ses, &rqst,
		&resp_buftype, flags, &rsp_iov);
		cifs_small_buf_release(req);
		rsp = (struct smb2_write_rsp *)rsp_iov.iov_base;

		if (rc) {
		@@ -3787,6 +3786,7 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms,
		io_parms->offset, *nbytes);
		}

		cifs_small_buf_release(req);
		free_rsp_buf(resp_buftype, rsp);
		return rc;
		}