As far as I know, the only support the US has sent to rebel groups is only non-military aid in the form of foodstuffs, GPS equipment, radios, etc. and training for personel of some rebel groups. But the US has so far refrained from sending any military equipment precisely because they fear that it would fall into the wrong hands. They also seem to be very careful on who they send aid to, choosing only secular groups or moderate Islamists. So why are some groups, especially the pro-Russian crowd, loudly accusing the US of causing chaos in Syria? What evidence do they have?
Non-military aid is still support, most of the stuff you listed is as important as having guns to running a successful rebellion. It was a while ago but the U.S. did send weapons to rebels in 2013. On a more controversial note it could be argued that the U.S. did attempt to indirectly support the rebels by leaving massive stockpiles of weapons and money in Iraq that were lightly guarded. Though since the U.S. is currently bombing those troops that argument is more than likely false. The U.S. has provided aid to the rebels so the Russian sources aren't entirely lying, through they may exaggerate the scale of aid, the real reason they are so critical is that Russia has been aiding Assad against the rebels. Both sides are helping to prolong the conflict and causing chaos.
because the US is really supporting the (rebels) they say that Alassad is dictator but why they didint say it before when the know Alassad he start to roul since the 2000 but if they think that Alassad is bad i say the (rebels) are much much worse i live in syria and see the real truth the poth side is bad but the rebels are much worse they will kill me only because iam not like them in religion and the chaos is not from russia or the US it is from the stupidity of the syrians