This allows setuid/setgid in containers. It also fixes some corner cases where kernel logic foregoes capability checks when uids are equivalent. The latter will need to be done throughout the whole kernel.
Signed-off-by: Serge E. Hallyn <[email protected]> --- kernel/sys.c | 35 ++++++++++++++++++++--------------- 1 files changed, 20 insertions(+), 15 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index 9b9b03b..2278e87 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -125,8 +125,10 @@ static int set_one_prio(struct task_struct *p, int niceval, int error) const struct cred *cred = current_cred(), *pcred = __task_cred(p); int no_nice; - if (pcred->uid != cred->euid && - pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) { + if (pcred->user->user_ns != cred->user->user_ns && + pcred->uid != cred->euid && + pcred->euid != cred->euid && + !ns_capable(pcred->user->user_ns, CAP_SYS_NICE)) { error = -EPERM; goto out; } @@ -496,7 +498,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) if (rgid != (gid_t) -1) { if (old->gid == rgid || old->egid == rgid || - capable(CAP_SETGID)) + ns_capable(current_user_ns(), CAP_SETGID)) new->gid = rgid; else goto error; @@ -505,7 +507,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) if (old->gid == egid || old->egid == egid || old->sgid == egid || - capable(CAP_SETGID)) + ns_capable(current_user_ns(), CAP_SETGID)) new->egid = egid; else goto error; @@ -540,7 +542,7 @@ SYSCALL_DEFINE1(setgid, gid_t, gid) old = current_cred(); retval = -EPERM; - if (capable(CAP_SETGID)) + if (ns_capable(current_user_ns(), CAP_SETGID)) new->gid = new->egid = new->sgid = new->fsgid = gid; else if (gid == old->gid || gid == old->sgid) new->egid = new->fsgid = gid; @@ -607,7 +609,7 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) new->uid = ruid; if (old->uid != ruid && old->euid != ruid && - !capable(CAP_SETUID)) + !ns_capable(current_user_ns(), CAP_SETUID)) goto error; } @@ -616,7 +618,7 @@ SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) if (old->uid != euid && old->euid != euid && old->suid != euid && - !capable(CAP_SETUID)) + !ns_capable(current_user_ns(), CAP_SETUID)) goto error; } @@ -664,7 +666,7 @@ SYSCALL_DEFINE1(setuid, uid_t, uid) old = current_cred(); retval = -EPERM; - if (capable(CAP_SETUID)) { + if (ns_capable(current_user_ns(), CAP_SETUID)) { new->suid = new->uid = uid; if (uid != old->uid) { retval = set_user(new); @@ -706,7 +708,7 @@ SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) old = current_cred(); retval = -EPERM; - if (!capable(CAP_SETUID)) { + if (!ns_capable(current_user_ns(), CAP_SETUID)) { if (ruid != (uid_t) -1 && ruid != old->uid && ruid != old->euid && ruid != old->suid) goto error; @@ -770,7 +772,7 @@ SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) old = current_cred(); retval = -EPERM; - if (!capable(CAP_SETGID)) { + if (!ns_capable(current_user_ns(), CAP_SETGID)) { if (rgid != (gid_t) -1 && rgid != old->gid && rgid != old->egid && rgid != old->sgid) goto error; @@ -830,7 +832,7 @@ SYSCALL_DEFINE1(setfsuid, uid_t, uid) if (uid == old->uid || uid == old->euid || uid == old->suid || uid == old->fsuid || - capable(CAP_SETUID)) { + ns_capable(current_user_ns(), CAP_SETUID)) { if (uid != old_fsuid) { new->fsuid = uid; if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) @@ -863,7 +865,7 @@ SYSCALL_DEFINE1(setfsgid, gid_t, gid) if (gid == old->gid || gid == old->egid || gid == old->sgid || gid == old->fsgid || - capable(CAP_SETGID)) { + ns_capable(current_user_ns(), CAP_SETGID)) { if (gid != old_fsgid) { new->fsgid = gid; goto change_okay; @@ -1220,7 +1222,7 @@ SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) int errno; char tmp[__NEW_UTS_LEN]; - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; if (len < 0 || len > __NEW_UTS_LEN) return -EINVAL; @@ -1335,6 +1337,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource, rlim = tsk->signal->rlim + resource; task_lock(tsk->group_leader); if (new_rlim) { + /* Keep the capable check against init_user_ns until + cgroups can contain all limits */ if (new_rlim->rlim_max > rlim->rlim_max && !capable(CAP_SYS_RESOURCE)) retval = -EPERM; @@ -1379,13 +1383,14 @@ static int check_prlimit_permission(struct task_struct *task) const struct cred *cred = current_cred(), *tcred; tcred = __task_cred(task); - if ((cred->uid != tcred->euid || + if ((cred->user->user_ns != tcred->user->user_ns || + cred->uid != tcred->euid || cred->uid != tcred->suid || cred->uid != tcred->uid || cred->gid != tcred->egid || cred->gid != tcred->sgid || cred->gid != tcred->gid) && - !capable(CAP_SYS_RESOURCE)) { + !ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE)) { return -EPERM; } -- 1.7.0.4 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
