From: Aleksa Sarai <cyphar@cyphar.com>
To: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Christian Brauner <christian@brauner.io>,
Kees Cook <keescook@chromium.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Al Viro <viro@zeniv.linux.org.uk>,
Linus Torvalds <torvalds@linux-foundation.org>,
libc-alpha@sourceware.org, linux-api@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v4 2/4] clone3: switch to copy_struct_from_user()
Date: Tue, 1 Oct 2019 11:10:53 +1000 [thread overview]
Message-ID: <20191001011055.19283-3-cyphar@cyphar.com> (raw)
In-Reply-To: <20191001011055.19283-1-cyphar@cyphar.com>
The change is very straightforward, and helps unify the syscall
interface for struct-from-userspace syscalls. Additionally, explicitly
define CLONE_ARGS_SIZE_VER0 to match the other users of the
struct-extension pattern.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
---
include/uapi/linux/sched.h | 2 ++
kernel/fork.c | 34 +++++++---------------------------
2 files changed, 9 insertions(+), 27 deletions(-)
diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
index b3105ac1381a..0945805982b4 100644
--- a/include/uapi/linux/sched.h
+++ b/include/uapi/linux/sched.h
@@ -47,6 +47,8 @@ struct clone_args {
__aligned_u64 tls;
};
+#define CLONE_ARGS_SIZE_VER0 64 /* sizeof first published struct */
+
/*
* Scheduling policies
*/
diff --git a/kernel/fork.c b/kernel/fork.c
index f9572f416126..2ef529869c64 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2525,39 +2525,19 @@ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
#ifdef __ARCH_WANT_SYS_CLONE3
noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
struct clone_args __user *uargs,
- size_t size)
+ size_t usize)
{
+ int err;
struct clone_args args;
- if (unlikely(size > PAGE_SIZE))
+ if (unlikely(usize > PAGE_SIZE))
return -E2BIG;
-
- if (unlikely(size < sizeof(struct clone_args)))
+ if (unlikely(usize < CLONE_ARGS_SIZE_VER0))
return -EINVAL;
- if (unlikely(!access_ok(uargs, size)))
- return -EFAULT;
-
- if (size > sizeof(struct clone_args)) {
- unsigned char __user *addr;
- unsigned char __user *end;
- unsigned char val;
-
- addr = (void __user *)uargs + sizeof(struct clone_args);
- end = (void __user *)uargs + size;
-
- for (; addr < end; addr++) {
- if (get_user(val, addr))
- return -EFAULT;
- if (val)
- return -E2BIG;
- }
-
- size = sizeof(struct clone_args);
- }
-
- if (copy_from_user(&args, uargs, size))
- return -EFAULT;
+ err = copy_struct_from_user(&args, sizeof(args), uargs, usize);
+ if (err)
+ return err;
/*
* Verify that higher 32bits of exit_signal are unset and that
--
2.23.0
next prev parent reply other threads:[~2019-10-01 1:12 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-01 1:10 [PATCH v4 0/4] lib: introduce copy_struct_from_user() helper Aleksa Sarai
2019-10-01 1:10 ` [PATCH v4 1/4] " Aleksa Sarai
2019-10-01 1:58 ` Kees Cook
2019-10-01 2:31 ` Christian Brauner
2019-10-01 16:28 ` Kees Cook
2019-10-10 11:19 ` Michael Ellerman
2019-10-10 11:40 ` Aleksa Sarai
2019-10-10 16:43 ` Kees Cook
2019-10-11 2:24 ` [PATCH] usercopy: Avoid soft lockups in test_check_nonzero_user() Michael Ellerman
2019-10-11 3:48 ` Aleksa Sarai
2019-10-11 9:43 ` Christian Brauner
2019-10-16 12:28 ` Michael Ellerman
2019-10-16 12:45 ` Christian Brauner
2019-10-12 9:54 ` Michael Ellerman
2019-10-12 10:12 ` Aleksa Sarai
2019-10-16 12:27 ` [PATCH v2] " Michael Ellerman
2019-10-16 12:36 ` Aleksa Sarai
2019-10-16 12:50 ` Christian Brauner
2019-10-16 13:03 ` Christian Brauner
2019-10-16 22:00 ` Michael Ellerman
2019-10-17 6:09 ` Christian Brauner
2019-10-23 2:23 ` Michael Ellerman
2019-10-01 1:10 ` Aleksa Sarai [this message]
2019-10-01 2:32 ` [PATCH v4 2/4] clone3: switch to copy_struct_from_user() Christian Brauner
2019-10-01 1:10 ` [PATCH v4 3/4] sched_setattr: " Aleksa Sarai
2019-10-01 2:33 ` Christian Brauner
2019-10-01 1:10 ` [PATCH v4 4/4] perf_event_open: " Aleksa Sarai
2019-10-01 2:36 ` Christian Brauner
2019-10-01 16:01 ` [PATCH v4 0/4] lib: introduce copy_struct_from_user() helper Christian Brauner
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