// SPDX-License-Identifier: GPL-2.0 /* * Wrapper functions for 16bit uid back compatibility. All nicely tied * together in the faint hope we can take the out in five years time. */ #include <linux/mm.h> #include <linux/mman.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/prctl.h> #include <linux/capability.h> #include <linux/init.h> #include <linux/highuid.h> #include <linux/security.h> #include <linux/cred.h> #include <linux/syscalls.h> #include <linux/uaccess.h> SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) { return sys_chown(filename, low2highuid(user), low2highgid(group)); } SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) { return sys_lchown(filename, low2highuid(user), low2highgid(group)); } SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group) { return sys_fchown(fd, low2highuid(user), low2highgid(group)); } SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid) { return sys_setregid(low2highgid(rgid), low2highgid(egid)); } SYSCALL_DEFINE1(setgid16, old_gid_t, gid) { return sys_setgid(low2highgid(gid)); } SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid) { return sys_setreuid(low2highuid(ruid), low2highuid(euid)); } SYSCALL_DEFINE1(setuid16, old_uid_t, uid) { return sys_setuid(low2highuid(uid)); } SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid) { return sys_setresuid(low2highuid(ruid), low2highuid(euid), low2highuid(suid)); } SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruidp, old_uid_t __user *, euidp, old_uid_t __user *, suidp) { const struct cred *cred = current_cred(); int retval; old_uid_t ruid, euid, suid; ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid)); euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid)); suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid)); if (!(retval = put_user(ruid, ruidp)) && !(retval = put_user(euid, euidp))) retval = put_user(suid, suidp); return retval; } SYSCALL_DEFINE3(setresgid16, old_gid_t, rgid, old_gid_t, egid, old_gid_t, sgid) { return sys_setresgid(low2highgid(rgid), low2highgid(egid), low2highgid(sgid)); } SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgidp, old_gid_t __user *, egidp, old_gid_t __user *, sgidp) { const struct cred *cred = current_cred(); int retval; old_gid_t rgid, egid, sgid; rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid)); egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid)); sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid)); if (!(retval = put_user(rgid, rgidp)) && !(retval = put_user(egid, egidp))) retval = put_user(sgid, sgidp); return retval; } SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid) { return sys_setfsuid(low2highuid(uid)); } SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid) { return sys_setfsgid(low2highgid(gid)); } static int groups16_to_user(old_gid_t __user *grouplist, struct group_info *group_info) { struct user_namespace *user_ns = current_user_ns(); int i; old_gid_t group; kgid_t kgid; for (i = 0; i < group_info->ngroups; i++) { kgid = group_info->gid[i]; group = high2lowgid(from_kgid_munged(user_ns, kgid)); if (put_user(group, grouplist+i)) return -EFAULT; } return 0; } static int groups16_from_user(struct group_info *group_info, old_gid_t __user *grouplist) { struct user_namespace *user_ns = current_user_ns(); int i; old_gid_t group; kgid_t kgid; for (i = 0; i < group_info->ngroups; i++) { if (get_user(group, grouplist+i)) return -EFAULT; kgid = make_kgid(user_ns, low2highgid(group)); if (!gid_valid(kgid)) return -EINVAL; group_info->gid[i] = kgid; } return 0; } SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist) { const struct cred *cred = current_cred(); int i; if (gidsetsize < 0) return -EINVAL; i = cred->group_info->ngroups; if (gidsetsize) { if (i > gidsetsize) { i = -EINVAL; goto out; } if (groups16_to_user(grouplist, cred->group_info)) { i = -EFAULT; goto out; } } out: return i; } SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist) { struct group_info *group_info; int retval; if (!may_setgroups()) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; group_info = groups_alloc(gidsetsize); if (!group_info) return -ENOMEM; retval = groups16_from_user(group_info, grouplist); if (retval) { put_group_info(group_info); return retval; } retval = set_current_groups(group_info); put_group_info(group_info); return retval; } SYSCALL_DEFINE0(getuid16) { return high2lowuid(from_kuid_munged(current_user_ns(), current_uid())); } SYSCALL_DEFINE0(geteuid16) { return high2lowuid(from_kuid_munged(current_user_ns(), current_euid())); } SYSCALL_DEFINE0(getgid16) { return high2lowgid(from_kgid_munged(current_user_ns(), current_gid())); } SYSCALL_DEFINE0(getegid16) { return high2lowgid(from_kgid_munged(current_user_ns(), current_egid())); }