From: Colin Ian King <colin.king@canonical.com>
Date: Fri, 16 Oct 2020 14:33:51 +0000 (+0100)
Subject: lightnvm: fix out-of-bounds write to array devices->info[]
X-Git-Tag: v5.8.17~116
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd85f97e424bc43b2535b8c9c61789691f5d111a;p=thirdparty%2Fkernel%2Fstable.git

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

[ Upstream commit a48faebe65b0db55a73b9220c3d919eee849bb79 ]

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 <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c
index db38a68abb6c0..a6f4ca438bca1 100644
--- a/drivers/lightnvm/core.c
+++ b/drivers/lightnvm/core.c
@@ -1315,8 +1315,9 @@ 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;
 		}
 	}