• He Zhe's avatar
    kgdboc: Passing ekgdboc to command line causes panic · 1bd54d85
    He Zhe authored
    kgdboc_option_setup does not check input argument before passing it
    to strlen. The argument would be a NULL pointer if "ekgdboc", without
    its value, is set in command line and thus cause the following panic.
    
    PANIC: early exception 0xe3 IP 10:ffffffff8fbbb620 error 0 cr2 0x0
    [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #1
    [    0.000000] RIP: 0010:strlen+0x0/0x20
    ...
    [    0.000000] Call Trace
    [    0.000000]  ? kgdboc_option_setup+0x9/0xa0
    [    0.000000]  ? kgdboc_early_init+0x6/0x1b
    [    0.000000]  ? do_early_param+0x4d/0x82
    [    0.000000]  ? parse_args+0x212/0x330
    [    0.000000]  ? rdinit_setup+0x26/0x26
    [    0.000000]  ? parse_early_options+0x20/0x23
    [    0.000000]  ? rdinit_setup+0x26/0x26
    [    0.000000]  ? parse_early_param+0x2d/0x39
    [    0.000000]  ? setup_arch+0x2f7/0xbf4
    [    0.000000]  ? start_kernel+0x5e/0x4c2
    [    0.000000]  ? load_ucode_bsp+0x113/0x12f
    [    0.000000]  ? secondary_startup_64+0xa5/0xb0
    
    This patch adds a check to prevent the panic.
    
    Cc: stable@vger.kernel.org
    Cc: jason.wessel@windriver.com
    Cc: gregkh@linuxfoundation.org
    Cc: jslaby@suse.com
    Signed-off-by: default avatarHe Zhe <zhe.he@windriver.com>
    Reviewed-by: default avatarDaniel Thompson <daniel.thompson@linaro.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    1bd54d85
kgdboc.c 7.38 KB