@@ -650,11 +650,12 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
const struct cred *old;
struct cred *new;
int retval;
- kuid_t kruid, keuid, ksuid;
+ kuid_t kruid, keuid, ksuid, kfsuid;
kruid = make_kuid(ns, ruid);
keuid = make_kuid(ns, euid);
ksuid = make_kuid(ns, suid);
+ kfsuid = make_kfsuid(ns, euid);
if ((ruid != (uid_t) -1) && !uid_valid(kruid))
return -EINVAL;
@@ -665,6 +666,9 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
if ((suid != (uid_t) -1) && !uid_valid(ksuid))
return -EINVAL;
+ if ((euid != (uid_t) -1) && !uid_valid(kfsuid))
+ return -EINVAL;
+
new = prepare_creds();
if (!new)
return -ENOMEM;
@@ -692,11 +696,15 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
goto error;
}
}
- if (euid != (uid_t) -1)
+ if (euid != (uid_t) -1) {
new->euid = keuid;
+ } else {
+ uid_t fsuid = from_kuid_munged(new->user_ns, new->euid);
+ kfsuid = make_kfsuid(ns, fsuid);
+ }
if (suid != (uid_t) -1)
new->suid = ksuid;
- new->fsuid = new->euid;
+ new->fsuid = kfsuid;
retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
if (retval < 0)
Switch setresuid() to lookup fsids in the fsid mappings. If no fsid mappings are setup the behavior is unchanged, i.e. fsids are looked up in the id mappings. During setresuid() the kfsuid is set to the keuid corresponding the euid that is requested by userspace. If the requested euid is -1 the kfsuid is reset to the current keuid. For the latter case this means we need to lookup the corresponding userspace euid corresponding to the current keuid in the id mappings and translate this euid into the corresponding kfsuid in the fsid mappings. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- kernel/sys.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)