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auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mrezanin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=mrezanin@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.248, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason Wang , Dmitry Fleytman , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jan 14, 2021 at 02:15:59PM +0100, Philippe Mathieu-Daudé wrote: > +Jason +Dmitry > > On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > > When building qemu with GCC 11, compiling eth.c file produce following warning: > > > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > > attributes. > > > > As this usage is expected, suppress the warning temporarily through the function > > using this retyping. > > This is not expected, this is a bug... Thanks for confirmation, my initial idea was the same but then I got impression (do not remember where) that ip6_ext_hdr is not type where data are initially written to so the overflow here is expected. Mirek > > > > > Signed-off-by: Miroslav Rezanina > > --- > > net/eth.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/net/eth.c b/net/eth.c > > index 1e0821c5f8..b9bdd0435c 100644 > > --- a/net/eth.c > > +++ b/net/eth.c > > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > struct ip6_ext_hdr *ext_hdr, > > struct in6_address *dst_addr) > > { > > +#pragma GCC diagnostic push > > +#pragma GCC diagnostic ignored "-Warray-bounds" > > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; > > eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > > > if ((rthdr->rtype == 2) && > > Here we access after the 2 bytes filled... rthdr->rtype is somewhere on > eth_parse_ipv6_hdr's stack, its content is unknown. > > > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > } > > > > return false; > > +#pragma GCC diagnostic pop > > Nacked-by: Philippe Mathieu-Daudé > >