Description: vt: fix memory overlapping when deleting chars in the buffer
References:
Notes:
 carnil> Introduced in 81732c3b2fed ("tty vt: Fix line garbage in virtual console on
 carnil> command line edition"). Vulnerable versions: 3.7-rc1.
Bugs:
upstream: released (5.19-rc7) [39cdb68c64d84e71a4a717000b6e5de208ee60cc]
6.8-upstream-stable: N/A "Fixed before branching point"
6.7-upstream-stable: N/A "Fixed before branching point"
6.6-upstream-stable: N/A "Fixed before branching point"
6.1-upstream-stable: N/A "Fixed before branching point"
5.10-upstream-stable: released (5.10.132) [bfee93c9a6c395f9aa62268f1cedf64999844926]
4.19-upstream-stable: released (4.19.312) [c8686c014b5e872ba7e334f33ca553f14446fc29]
sid: released (5.18.14-1)
6.1-bookworm-security: N/A "Fixed before branching point"
5.10-bullseye-security: released (5.10.136-1)
4.19-buster-security: needed