Message ID | 1519119624-1268-8-git-send-email-geert+renesas@glider.be |
---|---|
State | New |
Headers | show |
Series | serial: Fix out-of-bounds accesses through DT aliases | expand |
On Tue, Feb 20, 2018 at 10:40 AM, Geert Uytterhoeven <geert+renesas@glider.be> wrote: > The sci_ports[] array is indexed using a value derived from the > "serialN" alias in DT, which may lead to an out-of-bounds access. > > Fix this by adding a range check. > > Note that the array size is defined by a Kconfig symbol > (CONFIG_SERIAL_SH_SCI_NR_UARTS), so this can even be triggered using a > legitimate DTB. > > Fixes: f650cdf1c115498e ("serial: sh-sci: Fix out-of-bounds access through DT alias") Fixes: 97ed9790c514066b ("serial: sh-sci: Remove unused platform data capabilities field") Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 4d14f321cbec95e0..0fb4784860da6188 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -3620,6 +3620,10 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, dev_err(&pdev->dev, "failed to get alias id (%d)\n", id); return NULL; } + if (id >= SCI_NPORTS) { + dev_err(&pdev->dev, "serial%d out of range\n", id); + return NULL; + } sp = &sci_ports[id]; *dev_id = id;
The sci_ports[] array is indexed using a value derived from the "serialN" alias in DT, which may lead to an out-of-bounds access. Fix this by adding a range check. Note that the array size is defined by a Kconfig symbol (CONFIG_SERIAL_SH_SCI_NR_UARTS), so this can even be triggered using a legitimate DTB. Fixes: f650cdf1c115498e ("serial: sh-sci: Fix out-of-bounds access through DT alias") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- drivers/tty/serial/sh-sci.c | 4 ++++ 1 file changed, 4 insertions(+)