diff options
| -rw-r--r-- | drivers/base/devtmpfs.c | 2 | ||||
| -rw-r--r-- | fs/init.c | 24 | ||||
| -rw-r--r-- | fs/open.c | 7 | ||||
| -rw-r--r-- | include/linux/init_syscalls.h | 1 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 2 | ||||
| -rw-r--r-- | init/do_mounts.c | 2 | ||||
| -rw-r--r-- | init/do_mounts_initrd.c | 4 |
7 files changed, 30 insertions, 12 deletions
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index e48aaba3166b..eac184e6d657 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -413,7 +413,7 @@ static int __init devtmpfs_setup(void *p) if (err) goto out; init_chdir("/.."); /* will traverse into overmounted root */ - ksys_chroot("."); + init_chroot("."); out: *(int *)p = err; complete(&setup_done); diff --git a/fs/init.c b/fs/init.c index 64d4e12eba93..2c78f24814dd 100644 --- a/fs/init.c +++ b/fs/init.c @@ -9,6 +9,7 @@ #include <linux/fs.h> #include <linux/fs_struct.h> #include <linux/init_syscalls.h> +#include <linux/security.h> #include "internal.h" int __init init_mount(const char *dev_name, const char *dir_name, @@ -54,6 +55,29 @@ int __init init_chdir(const char *filename) return error; } +int __init init_chroot(const char *filename) +{ + struct path path; + int error; + + error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path); + if (error) + return error; + error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); + if (error) + goto dput_and_out; + error = -EPERM; + if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) + goto dput_and_out; + error = security_path_chroot(&path); + if (error) + goto dput_and_out; + set_fs_root(current->fs, &path); +dput_and_out: + path_put(&path); + return error; +} + int __init init_unlink(const char *pathname) { return do_unlinkat(AT_FDCWD, getname_kernel(pathname)); diff --git a/fs/open.c b/fs/open.c index 723e0ac89893..f62f4752bb43 100644 --- a/fs/open.c +++ b/fs/open.c @@ -530,7 +530,7 @@ out: return error; } -int ksys_chroot(const char __user *filename) +SYSCALL_DEFINE1(chroot, const char __user *, filename) { struct path path; int error; @@ -563,11 +563,6 @@ out: return error; } -SYSCALL_DEFINE1(chroot, const char __user *, filename) -{ - return ksys_chroot(filename); -} - static int chmod_common(const struct path *path, umode_t mode) { struct inode *inode = path->dentry->d_inode; diff --git a/include/linux/init_syscalls.h b/include/linux/init_syscalls.h index 1e845910ae56..e07099a14b91 100644 --- a/include/linux/init_syscalls.h +++ b/include/linux/init_syscalls.h @@ -4,5 +4,6 @@ int __init init_mount(const char *dev_name, const char *dir_name, const char *type_page, unsigned long flags, void *data_page); int __init init_umount(const char *name, int flags); int __init init_chdir(const char *filename); +int __init init_chroot(const char *filename); int __init init_unlink(const char *pathname); int __init init_rmdir(const char *pathname); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 31fa67fb9894..e89d62e944dc 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1235,8 +1235,6 @@ asmlinkage long sys_ni_syscall(void); * Instead, use one of the functions which work equivalently, such as * the ksys_xyzyyz() functions prototyped below. */ - -int ksys_chroot(const char __user *filename); ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count); int ksys_fchown(unsigned int fd, uid_t user, gid_t group); ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count); diff --git a/init/do_mounts.c b/init/do_mounts.c index a7581c6e85f2..b5f9604d0c98 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -629,7 +629,7 @@ void __init prepare_namespace(void) out: devtmpfs_mount(); init_mount(".", "/", NULL, MS_MOVE, NULL); - ksys_chroot("."); + init_chroot("."); } static bool is_tmpfs; diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index 04627fd22a92..a6b447b191db 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -63,7 +63,7 @@ static int __init init_linuxrc(struct subprocess_info *info, struct cred *new) /* move initrd over / and chdir/chroot in initrd root */ init_chdir("/root"); init_mount(".", "/", NULL, MS_MOVE, NULL); - ksys_chroot("."); + init_chroot("."); ksys_setsid(); return 0; } @@ -101,7 +101,7 @@ static void __init handle_initrd(void) /* move initrd to rootfs' /old */ init_mount("..", ".", NULL, MS_MOVE, NULL); /* switch root and cwd back to / of rootfs */ - ksys_chroot(".."); + init_chroot(".."); if (new_decode_dev(real_root_dev) == Root_RAM0) { init_chdir("/old"); |