From 13ade4ac5c28e8a014fa85278f5a4270b215f906 Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Wed, 3 May 2023 16:49:26 +0900 Subject: 9p: virtio: fix unlikely null pointer deref in handle_rerror handle_rerror can dereference the pages pointer, but it is not necessarily set for small payloads. In practice these should be filtered out by the size check, but might as well double-check explicitly. This fixes the following scan-build warnings: net/9p/trans_virtio.c:401:24: warning: Dereference of null pointer [core.NullDereference] memcpy_from_page(to, *pages++, offs, n); ^~~~~~~~ net/9p/trans_virtio.c:406:23: warning: Dereference of null pointer (loaded from variable 'pages') [core.NullDereference] memcpy_from_page(to, *pages, offs, size); ^~~~~~ Reviewed-by: Simon Horman Signed-off-by: Dominique Martinet Signed-off-by: Eric Van Hensbergen --- net/9p/trans_virtio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 3c27ffb781e3..2c9495ccda6b 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -384,7 +384,7 @@ static void handle_rerror(struct p9_req_t *req, int in_hdr_len, void *to = req->rc.sdata + in_hdr_len; // Fits entirely into the static data? Nothing to do. - if (req->rc.size < in_hdr_len) + if (req->rc.size < in_hdr_len || !pages) return; // Really long error message? Tough, truncate the reply. Might get -- cgit v1.2.3