[PATCH AUTOSEL 5.4 149/205] SUNRPC: Fix another issue with MIC buffer space
From: Sasha Levin <sashal@kernel.org>
Date: 2020-01-16 19:22:11
Also in:
linux-nfs, lkml, stable
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
From: Chuck Lever <redacted>
[ Upstream commit e8d70b321ecc9b23d09b8df63e38a2f73160c209 ]
xdr_shrink_pagelen() BUG's when @len is larger than buf->page_len.
This can happen when xdr_buf_read_mic() is given an xdr_buf with
a small page array (like, only a few bytes).
Instead, just cap the number of bytes that xdr_shrink_pagelen()
will move.
Fixes: 5f1bc39979d ("SUNRPC: Fix buffer handling of GSS MIC ... ")
Signed-off-by: Chuck Lever <redacted>
Reviewed-by: Benjamin Coddington <redacted>
Signed-off-by: Trond Myklebust <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sunrpc/xdr.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 14ba9e72a204..f3104be8ff5d 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c@@ -436,13 +436,12 @@ xdr_shrink_bufhead(struct xdr_buf *buf, size_t len) } /** - * xdr_shrink_pagelen + * xdr_shrink_pagelen - shrinks buf->pages by up to @len bytes * @buf: xdr_buf * @len: bytes to remove from buf->pages * - * Shrinks XDR buffer's page array buf->pages by - * 'len' bytes. The extra data is not lost, but is instead - * moved into the tail. + * The extra data is not lost, but is instead moved into buf->tail. + * Returns the actual number of bytes moved. */ static unsigned int xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
@@ -455,8 +454,8 @@ xdr_shrink_pagelen(struct xdr_buf *buf, size_t len) result = 0; tail = buf->tail; - BUG_ON (len > pglen); - + if (len > buf->page_len) + len = buf-> page_len; tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len; /* Shift the tail first */
--
2.20.1