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authorChuck Lever <chuck.lever@oracle.com>2020-06-25 11:32:34 -0400
committerSasha Levin <sashal@kernel.org>2020-06-30 15:37:12 -0400
commit7b99577ff376d58addf149eebe0ffff46351b3d7 (patch)
treefea34e0dd554996b02e7d414af615a0d2508e4a2 /net/sunrpc/xdr.c
parentc27d205baa8255ad152f26064ecf1fddd0258a5f (diff)
SUNRPC: Properly set the @subbuf parameter of xdr_buf_subsegment()
commit 89a3c9f5b9f0bcaa9aea3e8b2a616fcaea9aad78 upstream. @subbuf is an output parameter of xdr_buf_subsegment(). A survey of call sites shows that @subbuf is always uninitialized before xdr_buf_segment() is invoked by callers. There are some execution paths through xdr_buf_subsegment() that do not set all of the fields in @subbuf, leaving some pointer fields containing garbage addresses. Subsequent processing of that buffer then results in a page fault. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sunrpc/xdr.c')
-rw-r--r--net/sunrpc/xdr.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 451ca7ec321c..7ef37054071f 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -1118,6 +1118,7 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
base = 0;
} else {
base -= buf->head[0].iov_len;
+ subbuf->head[0].iov_base = buf->head[0].iov_base;
subbuf->head[0].iov_len = 0;
}
@@ -1130,6 +1131,8 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
base = 0;
} else {
base -= buf->page_len;
+ subbuf->pages = buf->pages;
+ subbuf->page_base = 0;
subbuf->page_len = 0;
}
@@ -1141,6 +1144,7 @@ xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
base = 0;
} else {
base -= buf->tail[0].iov_len;
+ subbuf->tail[0].iov_base = buf->tail[0].iov_base;
subbuf->tail[0].iov_len = 0;
}