Anyplace where the roof plane meets a vertical wall such as a dormer a chimney or a split level roof flashing is necessary.
Flashing a fieldstone chimney along siding.
I ve looked around a bit and all the details i can find only deal with chimney roof flashing.
A second layer of metal is embedded in the chimney mortar joints and folded down to cover the top of the step flashing.
The first is called step flashing.
Proper flashing around a chimney includes two layers.
The house will receive a cement style siding panel with no inside corner trim against the brick.
Once the pan flashing is in place nail it to the roof sheathing and lay the shingles over the flashing.
The other measures should have been taken before the siding was installed.
Sections of l shaped sheet metal are woven into the shingle courses and lapped up the side of the chimney.
On each end of the pan flashing cut about 1 1 2 in.
If this is running along the side of the house and not by the roof then maybe caulk at this point.
Next comes the counterflashing.
Pieces of 18 inch wide flashing installed prior to the brick work but on top of the house wrap in a stepped fashion periodically laying on top of the lapped upper portion of the siding to get the water back to the exterior of the wall is more along the lines that i would be thinking of.