From: Jiri Slaby jslaby@suse.cz
commit 7127d24372bf23675a36edc64d092dc7fd92ebe8 upstream.
init_r_port can access pc104 array out of bounds. pc104 is a 2D array defined to have 4 members. Each member has 8 submembers. * we can have more than 4 (PCI) boards, i.e. [board] can be OOB * line is not modulo-ed by anything, so the first line on the second board can be 4, on the 3rd 12 or alike (depending on previously registered boards). It's zero only on the first line of the first board. So even [line] can be OOB, quite soon (with the 2nd registered board already).
This code is broken for ages, so just avoid the OOB accesses and don't try to fix it as we would need to find out the correct line number. Use the default: RS232, if we are out.
Generally, if anyone needs to set the interface types, a module parameter is past the last thing that should be used for this purpose. The parameters' description says it's for ISA cards anyway.
Signed-off-by: Jiri Slaby jslaby@suse.cz Cc: stable stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Link: https://lore.kernel.org/r/20200417105959.15201-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/rocket.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)
--- a/drivers/tty/rocket.c +++ b/drivers/tty/rocket.c @@ -645,18 +645,21 @@ static void init_r_port(int board, int a info->port.ops = &rocket_port_ops; init_completion(&info->close_wait); info->flags &= ~ROCKET_MODE_MASK; - switch (pc104[board][line]) { - case 422: - info->flags |= ROCKET_MODE_RS422; - break; - case 485: - info->flags |= ROCKET_MODE_RS485; - break; - case 232: - default: + if (board < ARRAY_SIZE(pc104) && line < ARRAY_SIZE(pc104_1)) + switch (pc104[board][line]) { + case 422: + info->flags |= ROCKET_MODE_RS422; + break; + case 485: + info->flags |= ROCKET_MODE_RS485; + break; + case 232: + default: + info->flags |= ROCKET_MODE_RS232; + break; + } + else info->flags |= ROCKET_MODE_RS232; - break; - }
info->intmask = RXF_TRIG | TXFIFO_MT | SRC_INT | DELTA_CD | DELTA_CTS | DELTA_DSR; if (sInitChan(ctlp, &info->channel, aiop, chan) == 0) {