2020-10-16 15:53:58

by Colin King

Subject: [PATCH] lightnvm: fix out-of-bounds write to array devices->info[]

From: Colin Ian King <[email protected]>

There is an off-by-one array check that can lead to a out-of-bounds
write to devices->info[i]. Fix this by checking by using >= rather
than > for the size check. Also replace hard-coded array size limit
with ARRAY_SIZE on the array.

Addresses-Coverity: ("Out-of-bounds write")
Fixes: cd9e9808d18f ("lightnvm: Support for Open-Channel SSDs")
Signed-off-by: Colin Ian King <[email protected]>
---
drivers/lightnvm/core.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index fe78bf0fdce5..f9f5dd38c697 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -1311,8 +1311,9 @@ static long nvm_ioctl_get_devices(struct file *file, void __user *arg)
strlcpy(info->bmname, "gennvm", sizeof(info->bmname));
i++;

- if (i > 31) {
- pr_err("max 31 devices can be reported.\n");
+ if (i >= ARRAY_SIZE(devices->info)) {
+ pr_err("max %zd devices can be reported.\n",
+ ARRAY_SIZE(devices->info));
break;
}
}
--
2.27.0

2020-10-16 18:47:18

by Jens Axboe

Subject: Re: [PATCH] lightnvm: fix out-of-bounds write to array devices->info[]

On 10/16/20 8:33 AM, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> There is an off-by-one array check that can lead to a out-of-bounds
> write to devices->info[i]. Fix this by checking by using >= rather
> than > for the size check. Also replace hard-coded array size limit
> with ARRAY_SIZE on the array.

Applied, thanks.

--
Jens Axboe