diff options
Diffstat (limited to 'kernel/uid16.c')
| -rw-r--r-- | kernel/uid16.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/kernel/uid16.c b/kernel/uid16.c new file mode 100644 index 0000000000..af6925d859 --- /dev/null +++ b/kernel/uid16.c @@ -0,0 +1,221 @@ +// 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> + +#include "uid16.h" + +SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) +{ + return ksys_chown(filename, low2highuid(user), low2highgid(group)); +} + +SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group) +{ + return ksys_lchown(filename, low2highuid(user), low2highgid(group)); +} + +SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group) +{ + return ksys_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; + } + + groups_sort(group_info); + 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())); +} |