extcon: max77843: add guard element in array

This patch adds guard element in cable array to check last element.
This fixes following out of bounds access:
    ==================================================================
    BUG: KASan: out of bounds access in extcon_dev_register+0xc0/0x978 at addr ffffffc001bcc440
    Read of size 8 by task swapper/0/1
    page:ffffffbdc086f300 count:1 mapcount:0 mapping:          (null) index:0x0
    flags: 0x400(reserved)
    page dumped because: kasan: bad access detected
    Address belongs to variable max77843_extcon_cable+0x60/0xf00
    CPU: 5 PID: 1 Comm: swapper/0 Not tainted 4.1.0-00839-gb91c2a6-dirty #3
    Hardware name: Samsung TM2 board (DT)
    Call trace:
    [<ffffffc00008bc58>] dump_backtrace+0x0/0x1d8
    [<ffffffc00008be40>] show_stack+0x10/0x20
    [<ffffffc000eee3a4>] dump_stack+0x80/0xd4
    [<ffffffc00021e4f0>] kasan_report_error+0x3e0/0x408
    [<ffffffc00021e9ec>] kasan_report+0x44/0x50
    [<ffffffc00021d2dc>] __asan_load8+0x94/0xb0
    [<ffffffc000a78904>] extcon_dev_register+0xbc/0x978
    [<ffffffc000a791f8>] devm_extcon_dev_register+0x38/0x90
    [<ffffffc000a7cab8>] max77843_muic_probe+0x1e0/0x5f0
    [<ffffffc0006dc724>] platform_drv_probe+0x64/0xf8
    [<ffffffc0006d9ae8>] driver_probe_device+0x1f0/0x3a8
    [<ffffffc0006d9de0>] __driver_attach+0xc8/0xd0
    [<ffffffc0006d6fac>] bus_for_each_dev+0xd4/0x138
    [<ffffffc0006d932c>] driver_attach+0x2c/0x40
    [<ffffffc0006d8dfc>] bus_add_driver+0x214/0x2e8
    [<ffffffc0006dab40>] driver_register+0xb0/0x1c0
    [<ffffffc0006dc618>] __platform_driver_register+0xa8/0xb8
    [<ffffffc00179f6c0>] max77843_muic_init+0x14/0x20
    [<ffffffc000082ae4>] do_one_initcall+0xec/0x240
    [<ffffffc001755e50>] kernel_init_freeable+0x288/0x330
    [<ffffffc000eeab1c>] kernel_init+0xc/0xf0
    Memory state around the buggy address:
     ffffffc001bcc300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     ffffffc001bcc380: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00
    >ffffffc001bcc400: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00
                                               ^
     ffffffc001bcc480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     ffffffc001bcc500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    ==================================================================

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>

diff --git a/drivers/extcon/extcon-max77843.c b/drivers/extcon/extcon-max77843.c
index 85d4e20..f6fcaeb 100644 (file)
--- a/drivers/extcon/extcon-max77843.c
+++ b/drivers/extcon/extcon-max77843.c
@@ -149,6 +149,7 @@ static const char *max77843_extcon_cable[] = {
        [MAX77843_CABLE_JIG_USB_OFF]            = "JIG-USB-OFF",
        [MAX77843_CABLE_JIG_UART_ON]            = "JIG-UART-ON",
        [MAX77843_CABLE_JIG_UART_OFF]           = "JIG-UART-OFF",
+       NULL,
 };
 
 struct max77843_muic_irq {