Messages in this thread Patch in this message | | | Subject | Re: [PATCH] Fix NR_KEYS off-by-one error | From | OGAWA Hirofumi <> | Date | Thu, 29 Jul 2004 01:46:37 +0900 |
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Andries Brouwer <aebr@win.tue.nl> writes:
> When an array has an arbitrary upper bound that can be changed > via a #define, and for some values of the upper bound a test > is superfluous, that does not mean that the test is superfluous.
OK. The patch is the following.
Any comments or suggestions? -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
[PATCH] Fix NR_KEYS off-by-one error
KDGKBENT ioctl can use 256 entries (0-255), but it was defined as key_map[NR_KEYS] (NR_KEYS == 255). The code seems also thinking it's 256.
key_map[0] = U(K_ALLOCATED); for (j = 1; j < NR_KEYS; j++) key_map[j] = U(K_HOLE);
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> ---
drivers/char/vt_ioctl.c | 6 ++++++ include/linux/keyboard.h | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-)
diff -puN include/linux/keyboard.h~nr_keys-off-by-one include/linux/keyboard.h --- linux-2.6.8-rc2/include/linux/keyboard.h~nr_keys-off-by-one 2004-07-28 03:37:12.000000000 +0900 +++ linux-2.6.8-rc2-hirofumi/include/linux/keyboard.h 2004-07-28 03:37:12.000000000 +0900 @@ -16,7 +16,7 @@ #define NR_SHIFT 9 -#define NR_KEYS 255 +#define NR_KEYS 256 #define MAX_NR_KEYMAPS 256 /* This means 128Kb if all keymaps are allocated. Only the superuser may increase the number of keymaps beyond MAX_NR_OF_USER_KEYMAPS. */ diff -puN drivers/char/vt_ioctl.c~nr_keys-off-by-one drivers/char/vt_ioctl.c --- linux-2.6.8-rc2/drivers/char/vt_ioctl.c~nr_keys-off-by-one 2004-07-29 01:31:12.000000000 +0900 +++ linux-2.6.8-rc2-hirofumi/drivers/char/vt_ioctl.c 2004-07-29 01:35:23.000000000 +0900 @@ -83,6 +83,12 @@ do_kdsk_ioctl(int cmd, struct kbentry __ if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry))) return -EFAULT; +#if NR_KEYS != 256 || MAX_NR_KEYMAPS != 256 +#error "you should check this too" + if (i >= NR_KEYS || s >= MAX_NR_KEYMAPS) + return -EINVAL; +#endif + switch (cmd) { case KDGKBENT: key_map = key_maps[s]; _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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