tty: serial: mpc52xx_uart: add bounds check for psc_num array index

psc_num is derived from port->mapbase bits 11:8, giving a range of
0-15, but the psc_mclk_clk and psc_ipg_clk arrays are sized to
MPC52xx_PSC_MAXNUM (12 when CONFIG_PPC_MPC512x is set). A malformed
device tree with bits 11:8 >= 12 would cause out-of-bounds writes
in mpc512x_psc_alloc_clock() and out-of-bounds reads/writes in
mpc512x_psc_relse_clock() and mpc512x_psc_endis_clock(). The same
unchecked index also appears in mpc512x_psc_handle_irq().

Add ARRAY_SIZE() bounds checks to all four functions before using
psc_num as an array index.

Assisted-by: Opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260530061025.11625-1-rosenp@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Rosen Penev 2026-05-29 23:10:25 -07:00 • committed by Greg Kroah-Hartman
commit 4d10588066