From: James Hogan <james.hogan@imgtec.com>
To: <linux-kernel@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>,
James Hogan <james.hogan@imgtec.com>,
"Kees Cook" <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH v2 09/11] test_user_copy: Check user string accessors
Date: Fri, 7 Aug 2015 16:22:02 +0100 [thread overview]
Message-ID: <1438960924-23628-10-git-send-email-james.hogan@imgtec.com> (raw)
In-Reply-To: <1438960924-23628-1-git-send-email-james.hogan@imgtec.com>
Add basic success/failure checking of the user string functions which
copy or find the length of userland strings.
The following cases are checked:
- strncpy_from_user() with legitimate user to kernel addresses, illegal
all-kernel and reversed addresses, and legitimate all-kernel
addresses.
- strnlen_user() with a legitimate user address, an illegal kernel
address, and a legitimate kernel address.
New tests:
- legitimate strncpy_from_user
- legitimate strnlen_user
- illegal all-kernel strncpy_from_user
- illegal reversed strncpy_from_user
- illegal strnlen_user
- legitimate all-kernel strncpy_from_user
- legitimate kernel strnlen_user
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
Changes in v2:
- Drop strlen_user test. Microblaze doesn't define it, and nothing
actually uses it. IMO it should be removed, and there's no point
testing it in the mean time.
---
lib/test_user_copy.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
index 450b4c379c61..56af2439d2be 100644
--- a/lib/test_user_copy.c
+++ b/lib/test_user_copy.c
@@ -70,6 +70,10 @@ static int __init test_user_copy_init(void)
"legitimate put_user failed");
ret |= test(clear_user(usermem, PAGE_SIZE) != 0,
"legitimate clear_user passed");
+ ret |= test(strncpy_from_user(kmem, usermem, PAGE_SIZE) < 0,
+ "legitimate strncpy_from_user failed");
+ ret |= test(strnlen_user(usermem, PAGE_SIZE) == 0,
+ "legitimate strnlen_user failed");
ret |= test(!access_ok(VERIFY_READ, usermem, PAGE_SIZE * 2),
"legitimate access_ok VERIFY_READ failed");
@@ -109,6 +113,14 @@ static int __init test_user_copy_init(void)
"illegal put_user passed");
ret |= test(clear_user((char __user *)kmem, PAGE_SIZE) != PAGE_SIZE,
"illegal kernel clear_user passed");
+ ret |= test(strncpy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
+ PAGE_SIZE) >= 0,
+ "illegal all-kernel strncpy_from_user passed");
+ ret |= test(strncpy_from_user(bad_usermem, (char __user *)kmem,
+ PAGE_SIZE) >= 0,
+ "illegal reversed strncpy_from_user passed");
+ ret |= test(strnlen_user((char __user *)kmem, PAGE_SIZE) != 0,
+ "illegal strnlen_user passed");
/*
* If unchecked user accesses (__*) on this architecture cannot access
@@ -175,6 +187,11 @@ static int __init test_user_copy_init(void)
"legitimate kernel put_user failed");
ret |= test(clear_user((char __user *)kmem, PAGE_SIZE) != 0,
"legitimate kernel clear_user failed");
+ ret |= test(strncpy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
+ PAGE_SIZE) < 0,
+ "legitimate all-kernel strncpy_from_user failed");
+ ret |= test(strnlen_user((char __user *)kmem, PAGE_SIZE) == 0,
+ "legitimate kernel strnlen_user failed");
ret |= test(!access_ok(VERIFY_READ, (char __user *)kmem, PAGE_SIZE * 2),
"legitimate kernel access_ok VERIFY_READ failed");
--
2.3.6
next prev parent reply other threads:[~2015-08-07 15:23 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-07 15:21 [PATCH v2 00/11] test_user_copy improvements James Hogan
2015-08-07 15:21 ` [PATCH v2 01/11] microblaze: Export __strnlen_user to modules James Hogan
2015-08-07 15:21 ` [PATCH v2 02/11] nios2: Export strncpy_from_user / strnlen_user " James Hogan
2015-08-10 8:10 ` Ley Foon Tan
2015-08-07 15:21 ` [PATCH v2 03/11] openrisc: Export __clear_user " James Hogan
2015-08-07 15:21 ` [PATCH v2 04/11] xtensa: Export __strnlen_user " James Hogan
2015-08-07 15:21 ` [PATCH v2 05/11] test_user_copy: Check legit kernel accesses James Hogan
2015-08-07 15:21 ` [PATCH v2 06/11] test_user_copy: Check unchecked accessors James Hogan
2015-08-07 15:22 ` [PATCH v2 07/11] test_user_copy: Check __copy_{to,from}_user_inatomic() James Hogan
2015-08-07 15:22 ` [PATCH v2 08/11] test_user_copy: Check __clear_user()/clear_user() James Hogan
2015-08-07 15:22 ` James Hogan [this message]
2015-08-07 15:22 ` [PATCH v2 10/11] test_user_copy: Check user compatibility accessors James Hogan
2015-08-07 15:22 ` [PATCH v2 11/11] test_user_copy: Check user checksum functions James Hogan
2015-08-07 23:51 ` [PATCH v2 00/11] test_user_copy improvements Kees Cook
2015-08-10 22:29 ` David Miller
2015-08-11 4:08 ` David Miller
2015-08-11 11:20 ` Geert Uytterhoeven
2015-08-12 21:34 ` David Miller
2015-08-11 11:07 ` James Hogan
2015-08-11 17:32 ` David Miller
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