On 6/24/22 14:54, Ilya Maximets wrote: > ofpbuf_reserve() can be called with a zero size for a buffer with > an unallocated data. It's a valid case, but we should not allow > evaluation of 'NULL + 0'. > > SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior lib/ofpbuf.c:469:30 > in > lib/ofpbuf.c:469:30: runtime error: applying zero offset to null pointer > 0 0xb2f890 in ofpbuf_reserve lib/ofpbuf.c:469:30 > 1 0xb2f9bc in ofpbuf_new_with_headroom lib/ofpbuf.c:179:5 > 2 0xb2f9bc in ofpbuf_clone_data_with_headroom lib/ofpbuf.c:228:24 > 3 0xb2f9bc in ofpbuf_clone_with_headroom lib/ofpbuf.c:199:18 > 4 0xb2f8ea in ofpbuf_clone lib/ofpbuf.c:189:12 > 5 0x6b3c57 in ukey_set_actions ofproto/ofproto-dpif-upcall.c:1712:5 > 6 0x6c4315 in ukey_create__ ofproto/ofproto-dpif-upcall.c:1738:5 > 7 0x6beed6 in ukey_create_from_upcall > ofproto/ofproto-dpif-upcall.c:1793:12 > 8 0x6beed6 in upcall_xlate ofproto/ofproto-dpif-upcall.c:1284:24 > 9 0x6beed6 in process_upcall ofproto/ofproto-dpif-upcall.c:1456:9 > 10 0x6bafb6 in recv_upcalls ofproto/ofproto-dpif-upcall.c:875:17 > 11 0x6b70fa in udpif_upcall_handler ofproto/ofproto-dpif-upcall.c:792:13 > 12 0xb4d5fa in ovsthread_wrapper lib/ovs-thread.c:422:12 > 13 0x7fe6922081ce in start_thread (/lib64/libpthread.so.0+0x81ce) > 14 0x7fe690e39dd2 in clone (/lib64/libc.so.6+0x39dd2) > > Signed-off-by: Ilya Maximets <[email protected]> > --- > lib/ofpbuf.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/lib/ofpbuf.c b/lib/ofpbuf.c > index 79ced46d7..679f3ba3e 100644 > --- a/lib/ofpbuf.c > +++ b/lib/ofpbuf.c > @@ -464,6 +464,10 @@ ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t > *n) > void > ofpbuf_reserve(struct ofpbuf *b, size_t size) > { > + if (!size) { > + return; > + } > + > ovs_assert(!b->size);
Just to be extra sure, I think I'd move the ovs_assert(!b->size) before your new check. Anyhow, it's ok without or it can be done at apply time: Acked-by: Dumitru Ceara <[email protected]> > ofpbuf_prealloc_tailroom(b, size); > b->data = (char*)b->data + size; Thanks! _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
