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Groups > linux.kernel > #1200931
| From | James Hogan <james.hogan@imgtec.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3/7] test_user_copy: Check __clear_user()/clear_user() |
| Date | 2015-08-05 18:00 +0200 |
| Message-ID | <pU9gK-5S2-11@gated-at.bofh.it> (permalink) |
| References | <pU974-5Ga-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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> Cc: 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 23fb9d15f50c..4ec2cfa916c1 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"); @@ -81,6 +83,8 @@ 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), @@ -99,6 +103,8 @@ 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 @@ -128,6 +134,8 @@ 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 /* @@ -148,6 +156,8 @@ 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"); @@ -164,6 +174,8 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 0/7] test_user_copy improvements James Hogan <james.hogan@imgtec.com> - 2015-08-05 17:50 +0200
[PATCH 7/7] test_user_copy: Check user checksum functions James Hogan <james.hogan@imgtec.com> - 2015-08-05 17:50 +0200
[PATCH 2/7] test_user_copy: Check unchecked accessors James Hogan <james.hogan@imgtec.com> - 2015-08-05 17:50 +0200
[PATCH 3/7] test_user_copy: Check __clear_user()/clear_user() James Hogan <james.hogan@imgtec.com> - 2015-08-05 18:00 +0200
[PATCH 1/7] test_user_copy: Check legit kernel accesses James Hogan <james.hogan@imgtec.com> - 2015-08-05 18:00 +0200
[PATCH 6/7] test_user_copy: Check user string accessors James Hogan <james.hogan@imgtec.com> - 2015-08-05 18:00 +0200
[PATCH 4/7] test_user_copy: Check __copy_in_user()/copy_in_user() James Hogan <james.hogan@imgtec.com> - 2015-08-05 18:00 +0200
[PATCH 5/7] test_user_copy: Check __copy_{to,from}_user_inatomic() James Hogan <james.hogan@imgtec.com> - 2015-08-05 18:00 +0200
Re: [PATCH 0/7] test_user_copy improvements Kees Cook <keescook@chromium.org> - 2015-08-05 22:30 +0200
Re: [PATCH 0/7] test_user_copy improvements James Hogan <james.hogan@imgtec.com> - 2015-08-06 18:30 +0200
Re: [PATCH 0/7] test_user_copy improvements Guenter Roeck <linux@roeck-us.net> - 2015-08-06 12:00 +0200
Re: [PATCH 0/7] test_user_copy improvements James Hogan <james.hogan@imgtec.com> - 2015-08-06 12:10 +0200
Re: [PATCH 0/7] test_user_copy improvements James Hogan <james.hogan@imgtec.com> - 2015-08-06 17:10 +0200
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