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| author | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2021-06-09 17:07:29 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-20 16:02:18 +0200 |
| commit | 9a4f77f171f68e5a275c4fabd8d78579af7b4950 (patch) | |
| tree | c023c7d6e1ed1b9f09061e706f1904956a2c9417 /net | |
| parent | 7c96a2ee45be41d5a167e6332d202086752c36bb (diff) | |
| download | linux-9a4f77f171f68e5a275c4fabd8d78579af7b4950.tar.gz linux-9a4f77f171f68e5a275c4fabd8d78579af7b4950.tar.bz2 linux-9a4f77f171f68e5a275c4fabd8d78579af7b4950.zip | |
sunrpc: Avoid a KASAN slab-out-of-bounds bug in xdr_set_page_base()
[ Upstream commit 6d1c0f3d28f98ea2736128ed3e46821496dc3a8c ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/xdr.c | 7 |
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; |