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>,
"Andrew Morton" <akpm@linux-foundation.org>
Subject: [PATCH v2 08/11] test_user_copy: Check __clear_user()/clear_user()
Date: Fri, 7 Aug 2015 16:22:01 +0100 [thread overview]
Message-ID: <1438960924-23628-9-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 __clear_user() and clear_user(),
which zero an area of user or kernel memory and return the number of
bytes left to clear.
This catches a couple of bugs in the MIPS Enhanced Virtual Memory (EVA)
implementation (which have already been fixed):
test_user_copy: legitimate kernel clear_user failed
test_user_copy: legitimate kernel __clear_user failed
Due to neither function checking the user address limit, and both
resorting to user access unconditionally.
New tests:
- legitimate clear_user
- legitimate __clear_user
- illegal kernel clear_user
- illegal kernel __clear_user
- legitimate kernel clear_user
- legitimate kernel __clear_user
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
lib/test_user_copy.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
index c002fc1286bd..450b4c379c61 100644
--- a/lib/test_user_copy.c
+++ b/lib/test_user_copy.c
@@ -68,6 +68,8 @@ static int __init test_user_copy_init(void)
"legitimate get_user failed");
ret |= test(put_user(value, (unsigned long __user *)usermem),
"legitimate put_user failed");
+ ret |= test(clear_user(usermem, PAGE_SIZE) != 0,
+ "legitimate clear_user passed");
ret |= test(!access_ok(VERIFY_READ, usermem, PAGE_SIZE * 2),
"legitimate access_ok VERIFY_READ failed");
@@ -85,6 +87,8 @@ static int __init test_user_copy_init(void)
"legitimate __get_user failed");
ret |= test(__put_user(value, (unsigned long __user *)usermem),
"legitimate __put_user failed");
+ ret |= test(__clear_user(usermem, PAGE_SIZE) != 0,
+ "legitimate __clear_user passed");
/* Invalid usage: none of these should succeed. */
ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
@@ -103,6 +107,8 @@ static int __init test_user_copy_init(void)
"illegal get_user passed");
ret |= test(!put_user(value, (unsigned long __user *)kmem),
"illegal put_user passed");
+ ret |= test(clear_user((char __user *)kmem, PAGE_SIZE) != PAGE_SIZE,
+ "illegal kernel clear_user passed");
/*
* If unchecked user accesses (__*) on this architecture cannot access
@@ -145,6 +151,8 @@ static int __init test_user_copy_init(void)
"illegal __get_user passed");
ret |= test(!__put_user(value, (unsigned long __user *)kmem),
"illegal __put_user passed");
+ ret |= test(__clear_user((char __user *)kmem, PAGE_SIZE) != PAGE_SIZE,
+ "illegal kernel __clear_user passed");
#endif
/*
@@ -165,6 +173,8 @@ static int __init test_user_copy_init(void)
"legitimate kernel get_user failed");
ret |= test(put_user(value, (unsigned long __user *)kmem),
"legitimate kernel put_user failed");
+ ret |= test(clear_user((char __user *)kmem, PAGE_SIZE) != 0,
+ "legitimate kernel clear_user failed");
ret |= test(!access_ok(VERIFY_READ, (char __user *)kmem, PAGE_SIZE * 2),
"legitimate kernel access_ok VERIFY_READ failed");
@@ -188,6 +198,8 @@ static int __init test_user_copy_init(void)
"legitimate kernel __get_user failed");
ret |= test(__put_user(value, (unsigned long __user *)kmem),
"legitimate kernel __put_user failed");
+ ret |= test(__clear_user((char __user *)kmem, PAGE_SIZE) != 0,
+ "legitimate kernel __clear_user failed");
/* Restore previous address limit. */
set_fs(fs);
--
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 ` James Hogan [this message]
2015-08-07 15:22 ` [PATCH v2 09/11] test_user_copy: Check user string accessors James Hogan
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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