From 9046625511ad8dfbc8c6c2de16b3532c43d68d48 Mon Sep 17 00:00:00 2001

From: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>

Date: Fri, 26 Feb 2021 15:00:23 -0600

Subject: [Backport 9046625511ad] ecryptfs: fix kernel panic with null dev_name

When mounting eCryptfs, a null "dev_name" argument to ecryptfs_mount()

causes a kernel panic if the parsed options are valid. The easiest way to

reproduce this is to call mount() from userspace with an existing

eCryptfs mount's options and a "source" argument of 0.

Error out if "dev_name" is null in ecryptfs_mount()

Fixes: 237fead61998 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig")

Cc: stable@vger.kernel.org

Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>

Signed-off-by: Tyler Hicks <code@tyhicks.com>

---

 src/main.c | 6 ++++++

 1 file changed, 6 insertions(+)

diff --git a/src/main.c b/src/main.c

index 77b96737b1ffbdeea6d22294530e85ce05464dde..d66bbd2df191e5cf69310243a711dd341e3822c7 100644

--- a/src/main.c

+++ b/src/main.c

@@ -492,6 +492,12 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags

 		goto out;

 	}

+	if (!dev_name) {

+		rc = -EINVAL;

+		err = "Device name cannot be null";

+		goto out;

+	}

+

 	rc = ecryptfs_parse_options(sbi, raw_data, &check_ruid);

 	if (rc) {

 		err = "Error parsing options";

-- 

2.31.1