From: Chuck Lever <chuck.lever@oracle.com> stable inclusion from stable-v5.10.129 commit 6a0b9512a6aa7b7835d8138f5ffdcb4789c093d4 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YNDQ Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit a23dd544debcda4ee4a549ec7de59e85c3c8345c upstream. Looks like there are still cases when "space_left - frag1bytes" can legitimately exceed PAGE_SIZE. Ensure that xdr->end always remains within the current encode buffer. Reported-by: Bruce Fields <bfields@fieldses.org> Reported-by: Zorro Lang <zlang@redhat.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216151 Fixes: 6c254bf3b637 ("SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- net/sunrpc/xdr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index c8ed6d3d5762..d84bb5037bb5 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -752,7 +752,7 @@ static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, */ xdr->p = (void *)p + frag2bytes; space_left = xdr->buf->buflen - xdr->buf->len; - if (space_left - nbytes >= PAGE_SIZE) + if (space_left - frag1bytes >= PAGE_SIZE) xdr->end = (void *)p + PAGE_SIZE; else xdr->end = (void *)p + space_left - frag1bytes; -- 2.20.1