linux-kernel - [RFC PATCH 19/35] syscalls: do not call sys

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180311105557.20807-20-linux@dominikbrodowski.net>
Date:   Sun, 11 Mar 2018 11:55:41 +0100
From:   Dominik Brodowski <linux@...inikbrodowski.net>
To:     linux-kernel@...r.kernel.org, luto@...nel.org,
        torvalds@...ux-foundation.org, mingo@...nel.org,
        viro@...iv.linux.org.uk, akpm@...ux-foundation.org
Subject: [RFC PATCH 19/35] syscalls: do not call sys_unshare() within the kernel

CC: Al Viro <viro@...iv.linux.org.uk>
CC: Andrew Morton <akpm@...ux-foundation.org>
CC: Ingo Molnar <mingo@...nel.org>
Signed-off-by: Dominik Brodowski <linux@...inikbrodowski.net>
---
 drivers/base/devtmpfs.c  | 2 +-
 include/linux/syscalls.h | 1 +
 init/do_mounts_initrd.c  | 2 +-
 kernel/fork.c            | 7 ++++++-
 4 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 5743f04014ca..d6f37537275c 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -380,7 +380,7 @@ static int devtmpfsd(void *p)
 {
 	char options[] = "mode=0755";
 	int *err = p;
-	*err = sys_unshare(CLONE_NEWNS);
+	*err = ksys_unshare(CLONE_NEWNS);
 	if (*err)
 		goto out;
 	*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 51dd1e9185e1..1a17128394b7 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -954,5 +954,6 @@ int ksys_umount(char __user *name, int flags);
 int ksys_dup(unsigned int fildes);
 int ksys_chroot(const char __user *filename);
 ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count);
+int ksys_unshare(unsigned long unshare_flags);
 
 #endif
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index 71293265ac4b..414284dadc64 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -36,7 +36,7 @@ __setup("noinitrd", no_initrd);
 
 static int init_linuxrc(struct subprocess_info *info, struct cred *new)
 {
-	sys_unshare(CLONE_FS | CLONE_FILES);
+	ksys_unshare(CLONE_FS | CLONE_FILES);
 	/* stdin/stdout/stderr for /linuxrc */
 	sys_open("/dev/console", O_RDWR, 0);
 	ksys_dup(0);
diff --git a/kernel/fork.c b/kernel/fork.c
index b1e031aac9db..f71b67dc156d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2354,7 +2354,7 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
  * constructed. Here we are modifying the current, active,
  * task_struct.
  */
-SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
+int ksys_unshare(unsigned long unshare_flags)
 {
 	struct fs_struct *fs, *new_fs = NULL;
 	struct files_struct *fd, *new_fd = NULL;
@@ -2470,6 +2470,11 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
 	return err;
 }
 
+SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
+{
+	return ksys_unshare(unshare_flags);
+}
+
 /*
  *	Helper to unshare the files of the current task.
  *	We don't want to expose copy_files internals to
-- 
2.16.2