From 8610047ca89f4855ae0546dfc8db122d28deb50d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 20 May 2021 15:33:30 -0700 Subject: [PATCH] cm4000_cs: Use struct_group() to zero struct cm4000_dev region In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Add struct_group() to mark region of struct cm4000_dev that should be initialized to zero. Cc: Harald Welte Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Signed-off-by: Kees Cook Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/lkml/YQDvxAofJlI1JoGZ@kroah.com --- drivers/char/pcmcia/cm4000_cs.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c index 8f1bce0b4fe5..adaec8fd4b16 100644 --- a/drivers/char/pcmcia/cm4000_cs.c +++ b/drivers/char/pcmcia/cm4000_cs.c @@ -116,8 +116,9 @@ struct cm4000_dev { wait_queue_head_t atrq; /* wait for ATR valid */ wait_queue_head_t readq; /* used by write to wake blk.read */ - /* warning: do not move this fields. + /* warning: do not move this struct group. * initialising to zero depends on it - see ZERO_DEV below. */ + struct_group(init, unsigned char atr_csum; unsigned char atr_len_retry; unsigned short atr_len; @@ -140,12 +141,10 @@ struct cm4000_dev { struct timer_list timer; /* used to keep monitor running */ int monitor_running; + ); }; -#define ZERO_DEV(dev) \ - memset(&dev->atr_csum,0, \ - sizeof(struct cm4000_dev) - \ - offsetof(struct cm4000_dev, atr_csum)) +#define ZERO_DEV(dev) memset(&((dev)->init), 0, sizeof((dev)->init)) static struct pcmcia_device *dev_table[CM4000_MAX_DEV]; static struct class *cmm_class;