The patch titled
userns: user namespaces: convert several capable() calls
has been added to the -mm tree. Its filename is
userns-user-namespaces-convert-several-capable-calls.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: userns: user namespaces: convert several capable() calls
From: "Serge E. Hallyn" <serge@xxxxxxxxxx>
CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(),
because the resource comes from current's own ipc namespace.
setuid/setgid are to uids in own namespace, so again checks can be against
current_user_ns().
Changelog:
Jan 11: Use task_ns_capable() in place of sched_capable().
Jan 11: Use nsown_capable() as suggested by Bastian Blank.
Jan 11: Clarify (hopefully) some logic in futex and sched.c
Feb 15: use ns_capable for ipc, not nsown_capable
Signed-off-by: Serge E. Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: James Morris <jmorris@xxxxxxxxx>
Cc: Kees Cook <kees.cook@xxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/shm.c | 2 +-
ipc/util.c | 5 +++--
kernel/futex.c | 11 ++++++++++-
kernel/futex_compat.c | 11 ++++++++++-
kernel/groups.c | 2 +-
kernel/sched.c | 9 ++++++---
kernel/uid16.c | 2 +-
7 files changed, 32 insertions(+), 10 deletions(-)
diff -puN ipc/shm.c~userns-user-namespaces-convert-several-capable-calls ipc/shm.c
--- a/ipc/shm.c~userns-user-namespaces-convert-several-capable-calls
+++ a/ipc/shm.c
@@ -773,7 +773,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int,
audit_ipc_obj(&(shp->shm_perm));
- if (!capable(CAP_IPC_LOCK)) {
+ if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
uid_t euid = current_euid();
err = -EPERM;
if (euid != shp->shm_perm.uid &&
diff -puN ipc/util.c~userns-user-namespaces-convert-several-capable-calls ipc/util.c
--- a/ipc/util.c~userns-user-namespaces-convert-several-capable-calls
+++ a/ipc/util.c
@@ -627,7 +627,7 @@ int ipcperms (struct kern_ipc_perm *ipcp
granted_mode >>= 3;
/* is there some bit set in requested_mode but not in granted_mode? */
if ((requested_mode & ~granted_mode & 0007) &&
- !capable(CAP_IPC_OWNER))
+ !ns_capable(current->nsproxy->ipc_ns->user_ns, CAP_IPC_OWNER))
return -1;
return security_ipc_permission(ipcp, flag);
@@ -800,7 +800,8 @@ struct kern_ipc_perm *ipcctl_pre_down(st
euid = current_euid();
if (euid == ipcp->cuid ||
- euid == ipcp->uid || capable(CAP_SYS_ADMIN))
+ euid == ipcp->uid ||
+ ns_capable(current->nsproxy->ipc_ns->user_ns, CAP_SYS_ADMIN))
return ipcp;
err = -EPERM;
diff -puN kernel/futex.c~userns-user-namespaces-convert-several-capable-calls kernel/futex.c
--- a/kernel/futex.c~userns-user-namespaces-convert-several-capable-calls
+++ a/kernel/futex.c
@@ -2423,10 +2423,19 @@ SYSCALL_DEFINE3(get_robust_list, int, pi
goto err_unlock;
ret = -EPERM;
pcred = __task_cred(p);
+ /* If victim is in different user_ns, then uids are not
+ comparable, so we must have CAP_SYS_PTRACE */
+ if (cred->user->user_ns != pcred->user->user_ns) {
+ if (!ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
+ goto err_unlock;
+ goto ok;
+ }
+ /* If victim is in same user_ns, then uids are comparable */
if (cred->euid != pcred->euid &&
cred->euid != pcred->uid &&
- !capable(CAP_SYS_PTRACE))
+ !ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
goto err_unlock;
+ok:
head = p->robust_list;
rcu_read_unlock();
}
diff -puN kernel/futex_compat.c~userns-user-namespaces-convert-several-capable-calls kernel/futex_compat.c
--- a/kernel/futex_compat.c~userns-user-namespaces-convert-several-capable-calls
+++ a/kernel/futex_compat.c
@@ -153,10 +153,19 @@ compat_sys_get_robust_list(int pid, comp
goto err_unlock;
ret = -EPERM;
pcred = __task_cred(p);
+ /* If victim is in different user_ns, then uids are not
+ comparable, so we must have CAP_SYS_PTRACE */
+ if (cred->user->user_ns != pcred->user->user_ns) {
+ if (!ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
+ goto err_unlock;
+ goto ok;
+ }
+ /* If victim is in same user_ns, then uids are comparable */
if (cred->euid != pcred->euid &&
cred->euid != pcred->uid &&
- !capable(CAP_SYS_PTRACE))
+ !ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
goto err_unlock;
+ok:
head = p->compat_robust_list;
rcu_read_unlock();
}
diff -puN kernel/groups.c~userns-user-namespaces-convert-several-capable-calls kernel/groups.c
--- a/kernel/groups.c~userns-user-namespaces-convert-several-capable-calls
+++ a/kernel/groups.c
@@ -233,7 +233,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsi
struct group_info *group_info;
int retval;
- if (!capable(CAP_SETGID))
+ if (!nsown_capable(CAP_SETGID))
return -EPERM;
if ((unsigned)gidsetsize > NGROUPS_MAX)
return -EINVAL;
diff -puN kernel/sched.c~userns-user-namespaces-convert-several-capable-calls kernel/sched.c
--- a/kernel/sched.c~userns-user-namespaces-convert-several-capable-calls
+++ a/kernel/sched.c
@@ -4899,8 +4899,11 @@ static bool check_same_owner(struct task
rcu_read_lock();
pcred = __task_cred(p);
- match = (cred->euid == pcred->euid ||
- cred->euid == pcred->uid);
+ if (cred->user->user_ns == pcred->user->user_ns)
+ match = (cred->euid == pcred->euid ||
+ cred->euid == pcred->uid);
+ else
+ match = false;
rcu_read_unlock();
return match;
}
@@ -5225,7 +5228,7 @@ long sched_setaffinity(pid_t pid, const
goto out_free_cpus_allowed;
}
retval = -EPERM;
- if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
+ if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE))
goto out_unlock;
retval = security_task_setscheduler(p);
diff -puN kernel/uid16.c~userns-user-namespaces-convert-several-capable-calls kernel/uid16.c
--- a/kernel/uid16.c~userns-user-namespaces-convert-several-capable-calls
+++ a/kernel/uid16.c
@@ -189,7 +189,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidset
struct group_info *group_info;
int retval;
- if (!capable(CAP_SETGID))
+ if (!nsown_capable(CAP_SETGID))
return -EPERM;
if ((unsigned)gidsetsize > NGROUPS_MAX)
return -EINVAL;
_
Patches currently in -mm which might be from serge@xxxxxxxxxx are
lib-hexdumpc-make-hex2bin-return-the-updated-src-address.patch
fs-binfmt_miscc-use-kernels-hex_to_bin-method.patch
fs-binfmt_miscc-use-kernels-hex_to_bin-method-fix.patch
fs-binfmt_miscc-use-kernels-hex_to_bin-method-fix-fix.patch
pid-remove-the-child_reaper-special-case-in-init-mainc.patch
pidns-call-pid_ns_prepare_proc-from-create_pid_namespace.patch
procfs-kill-the-global-proc_mnt-variable.patch
userns-add-a-user_namespace-as-creator-owner-of-uts_namespace.patch
userns-security-make-capabilities-relative-to-the-user-namespace.patch
userns-allow-sethostname-in-a-container.patch
userns-allow-killing-tasks-in-your-own-or-child-userns.patch
userns-allow-ptrace-from-non-init-user-namespaces.patch
userns-user-namespaces-convert-all-capable-checks-in-kernel-sysc.patch
userns-add-a-user-namespace-owner-of-ipc-ns.patch
userns-user-namespaces-convert-several-capable-calls.patch
userns-userns-check-user-namespace-for-task-file-uid-equivalence-checks.patch
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