The white rice and white flour shouldn't be a problem.

We buy rice in 35 to 50 pound bags, which is a 9 month to 1.5 year supply - on purpose. The 35 pound bag is the only affordable way we can get one variety we like, and the plain old white stuff is just more convenient to "get it and get it over with." We usually store in old coffee cans, since they're "free" and pretty much bug-proof. On occasion we've found a can that got missed when we resupplied and may have been 2 years old (or a little more), and it was fine.

Common white flour (the multi-purpose kind) seems to be about as durable as paper. Pastry (high gluten) and other specialty flours (often whole grain) may have enough germ/fat/oil content to taste a bit off in a shorter time, and may have "performance problems." You use them because they do something different than the common stuff, and if they get old they may not do their trick as expected - and may not taste right as well. Whole grain flours/meals in general may have enough oil/fat content to go "off," and as you noted, may smell/taste odd.

Any can that has lost its "suck" should probably be discarded, because odds are pretty good that some gas-generating bug has been growing in them. If they're still tight, they should be safe; although they deefinitely can lose some flavor.

If the smell or taste has changed, the "chemistry" has changed, and stuff old enough to be "flavor challenged" may not have the same nutritional value as the fresh product. It's claimed that "time in storage" is how dinosaurs got turned into crude oil - which isn't too nourishing.

John