From: Chuck Lever chuck.lever@oracle.com
[ 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 chuck.lever@oracle.com Reviewed-by: Benjamin Coddington bcodding@redhat.com Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com 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 14ba9e72a2049..f3104be8ff5dc 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 */