commit
89a3c9f5b9f0bcaa9aea3e8b2a616fcaea9aad78 upstream.
@subbuf is an output parameter of xdr_buf_subsegment(). A survey of
call sites shows that @subbuf is always uninitialized before
xdr_buf_segment() is invoked by callers.
There are some execution paths through xdr_buf_subsegment() that do
not set all of the fields in @subbuf, leaving some pointer fields
containing garbage addresses. Subsequent processing of that buffer
then results in a page fault.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
base = 0;
} else {
base -= buf->head[0].iov_len;
+ subbuf->head[0].iov_base = buf->head[0].iov_base;
subbuf->head[0].iov_len = 0;
}
base = 0;
} else {
base -= buf->page_len;
+ subbuf->pages = buf->pages;
+ subbuf->page_base = 0;
subbuf->page_len = 0;
}
base = 0;
} else {
base -= buf->tail[0].iov_len;
+ subbuf->tail[0].iov_base = buf->tail[0].iov_base;
subbuf->tail[0].iov_len = 0;
}