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authorAnna Schumaker <Anna.Schumaker@Netapp.com>2021-06-10 00:07:29 +0300
committerTrond Myklebust <trond.myklebust@hammerspace.com>2021-06-14 02:36:49 +0300
commit6d1c0f3d28f98ea2736128ed3e46821496dc3a8c (patch)
tree5a22e9bd5f084e960186b8f370b8064452ca4a83 /net/sunrpc/xdr.c
parent3731d44bba8e0116b052b1b374476c5f6dd9a456 (diff)
downloadlinux-6d1c0f3d28f98ea2736128ed3e46821496dc3a8c.tar.xz
sunrpc: Avoid a KASAN slab-out-of-bounds bug in xdr_set_page_base()
This seems to happen fairly easily during READ_PLUS testing on NFS v4.2. I found that we could end up accessing xdr->buf->pages[pgnr] with a pgnr greater than the number of pages in the array. So let's just return early if we're setting base to a point at the end of the page data and let xdr_set_tail_base() handle setting up the buffer pointers instead. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Fixes: 8d86e373b0ef ("SUNRPC: Clean up helpers xdr_set_iov() and xdr_set_page_base()") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'net/sunrpc/xdr.c')
-rw-r--r--net/sunrpc/xdr.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 3964ff74ee51..ca10ba2626f2 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1230,10 +1230,9 @@ static unsigned int xdr_set_page_base(struct xdr_stream *xdr,
void *kaddr;
maxlen = xdr->buf->page_len;
- if (base >= maxlen) {
- base = maxlen;
- maxlen = 0;
- } else
+ if (base >= maxlen)
+ return 0;
+ else
maxlen -= base;
if (len > maxlen)
len = maxlen;