From: Aleksa Sarai <cyphar@cyphar.com>
To: Al Viro <viro@zeniv.linux.org.uk>,
Jeff Layton <jlayton@kernel.org>,
"J. Bruce Fields" <bfields@fieldses.org>,
Arnd Bergmann <arnd@arndb.de>,
David Howells <dhowells@redhat.com>,
Shuah Khan <shuah@kernel.org>,
Shuah Khan <skhan@linuxfoundation.org>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Christian Brauner <christian@brauner.io>
Cc: Aleksa Sarai <cyphar@cyphar.com>,
Eric Biederman <ebiederm@xmission.com>,
Andy Lutomirski <luto@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexei Starovoitov <ast@kernel.org>,
Kees Cook <keescook@chromium.org>, Jann Horn <jannh@google.com>,
Tycho Andersen <tycho@tycho.ws>,
David Drysdale <drysdale@google.com>,
Chanho Min <chanho.min@lge.com>, Oleg Nesterov <oleg@redhat.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Aleksa Sarai <asarai@suse.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
containers@lists.linux-foundation.org,
linux-alpha@vger.kernel.org, linux-api@vger.kernel.org,
linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
linux-xtensa@linux-xtensa.org, sparclinux@vger.kernel.org
Subject: [PATCH v12 04/12] perf_event_open: switch to copy_struct_from_user()
Date: Thu, 5 Sep 2019 06:19:25 +1000 [thread overview]
Message-ID: <20190904201933.10736-5-cyphar@cyphar.com> (raw)
In-Reply-To: <20190904201933.10736-1-cyphar@cyphar.com>
The change is very straightforward, and takes advantage of the (very
minor) efficiency improvements in copy_struct_from_user() -- that the
memchr_inv() check is done on a buffer instead of one-at-at-time with
get_user().
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
---
kernel/events/core.c | 45 ++++++++------------------------------------
1 file changed, 8 insertions(+), 37 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0463c1151bae..fe5f58443ba6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10498,55 +10498,26 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
u32 size;
int ret;
- if (!access_ok(uattr, PERF_ATTR_SIZE_VER0))
- return -EFAULT;
-
- /*
- * zero the full structure, so that a short copy will be nice.
- */
+ /* Zero the full structure, so that a short copy will be nice. */
memset(attr, 0, sizeof(*attr));
ret = get_user(size, &uattr->size);
if (ret)
return ret;
- if (size > PAGE_SIZE) /* silly large */
- goto err_size;
-
- if (!size) /* abi compat */
+ /* ABI compatibility quirk: */
+ if (!size)
size = PERF_ATTR_SIZE_VER0;
-
if (size < PERF_ATTR_SIZE_VER0)
goto err_size;
- /*
- * If we're handed a bigger struct than we know of,
- * ensure all the unknown bits are 0 - i.e. new
- * user-space does not rely on any kernel feature
- * extensions we dont know about yet.
- */
- if (size > sizeof(*attr)) {
- unsigned char __user *addr;
- unsigned char __user *end;
- unsigned char val;
-
- addr = (void __user *)uattr + sizeof(*attr);
- end = (void __user *)uattr + size;
-
- for (; addr < end; addr++) {
- ret = get_user(val, addr);
- if (ret)
- return ret;
- if (val)
- goto err_size;
- }
- size = sizeof(*attr);
+ ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size);
+ if (ret) {
+ if (ret == -E2BIG)
+ goto err_size;
+ return ret;
}
- ret = copy_from_user(attr, uattr, size);
- if (ret)
- return -EFAULT;
-
attr->size = size;
if (attr->__reserved_1)
--
2.23.0
next prev parent reply other threads:[~2019-09-04 20:21 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 20:19 [PATCH v12 00/12] namei: openat2(2) path resolution restrictions Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 01/12] lib: introduce copy_struct_{to,from}_user helpers Aleksa Sarai
2019-09-04 20:48 ` Linus Torvalds
2019-09-04 21:00 ` Randy Dunlap
2019-09-05 7:32 ` Peter Zijlstra
2019-09-05 9:26 ` Aleksa Sarai
2019-09-05 9:43 ` Peter Zijlstra
2019-09-05 10:57 ` Peter Zijlstra
2019-09-11 10:37 ` Aleksa Sarai
2019-09-05 13:35 ` Aleksa Sarai
2019-09-05 17:01 ` Aleksa Sarai
2019-09-05 8:43 ` Rasmus Villemoes
2019-09-05 9:50 ` Aleksa Sarai
2019-09-05 10:45 ` Christian Brauner
2019-09-05 9:09 ` Andreas Schwab
2019-09-05 10:13 ` [PATCH v12 01/12] lib: introduce copy_struct_{to, from}_user helpers Gabriel Paubert
2019-09-05 11:05 ` [PATCH v12 01/12] lib: introduce copy_struct_{to,from}_user helpers Christian Brauner
2019-09-05 11:17 ` Rasmus Villemoes
2019-09-05 11:29 ` Christian Brauner
2019-09-05 13:40 ` Aleksa Sarai
2019-09-05 11:09 ` Christian Brauner
2019-09-05 11:27 ` Aleksa Sarai
2019-09-05 11:40 ` Christian Brauner
2019-09-05 18:07 ` Al Viro
2019-09-05 18:23 ` Christian Brauner
2019-09-05 18:28 ` Al Viro
2019-09-05 18:35 ` Christian Brauner
2019-09-05 19:56 ` Aleksa Sarai
2019-09-05 22:31 ` Al Viro
2019-09-06 7:00 ` Christian Brauner
2019-09-05 23:00 ` Aleksa Sarai
2019-09-05 23:49 ` Al Viro
2019-09-06 0:09 ` Aleksa Sarai
2019-09-06 0:14 ` Al Viro
2019-09-04 20:19 ` [PATCH v12 02/12] clone3: switch to copy_struct_from_user() Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 03/12] sched_setattr: switch to copy_struct_{to,from}_user() Aleksa Sarai
2019-09-04 20:19 ` Aleksa Sarai [this message]
2019-09-04 20:19 ` [PATCH v12 05/12] namei: obey trailing magic-link DAC permissions Aleksa Sarai
2019-09-17 21:30 ` Jann Horn
2019-09-18 13:51 ` Aleksa Sarai
2019-09-18 15:46 ` Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 06/12] procfs: switch magic-link modes to be more sane Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 07/12] open: O_EMPTYPATH: procfs-less file descriptor re-opening Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 08/12] namei: O_BENEATH-style path resolution flags Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 09/12] namei: LOOKUP_IN_ROOT: chroot-like path resolution Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 10/12] namei: aggressively check for nd->root escape on ".." resolution Aleksa Sarai
2019-09-04 21:09 ` Linus Torvalds
2019-09-04 21:35 ` Linus Torvalds
2019-09-04 21:36 ` Linus Torvalds
2019-09-04 21:48 ` Aleksa Sarai
2019-09-04 22:16 ` Linus Torvalds
2019-09-04 22:31 ` David Howells
2019-09-04 22:38 ` Linus Torvalds
2019-09-04 23:29 ` Al Viro
2019-09-04 23:44 ` Linus Torvalds
2019-09-04 20:19 ` [PATCH v12 11/12] open: openat2(2) syscall Aleksa Sarai
2019-09-04 21:00 ` Randy Dunlap
2019-09-07 12:40 ` Jeff Layton
2019-09-07 16:58 ` Linus Torvalds
2019-09-07 17:42 ` Andy Lutomirski
2019-09-07 17:45 ` Linus Torvalds
2019-09-07 18:15 ` Andy Lutomirski
2019-09-10 6:35 ` Ingo Molnar
2019-09-08 16:24 ` Aleksa Sarai
2019-09-04 20:19 ` [PATCH v12 12/12] selftests: add openat2(2) selftests Aleksa Sarai
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