diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 44 |
1 files changed, 29 insertions, 15 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 291c9700be7..bb0efa5705e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -11,7 +11,7 @@ */ #include <linux/slab.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/fs.h> @@ -1344,13 +1344,24 @@ int kill_proc_info(int sig, struct siginfo *info, pid_t pid) return error; } +static int kill_as_cred_perm(const struct cred *cred, + struct task_struct *target) +{ + const struct cred *pcred = __task_cred(target); + if (cred->user_ns != pcred->user_ns) + return 0; + if (cred->euid != pcred->suid && cred->euid != pcred->uid && + cred->uid != pcred->suid && cred->uid != pcred->uid) + return 0; + return 1; +} + /* like kill_pid_info(), but doesn't use uid/euid of "current" */ -int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, - uid_t uid, uid_t euid, u32 secid) +int kill_pid_info_as_cred(int sig, struct siginfo *info, struct pid *pid, + const struct cred *cred, u32 secid) { int ret = -EINVAL; struct task_struct *p; - const struct cred *pcred; unsigned long flags; if (!valid_signal(sig)) @@ -1362,10 +1373,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, ret = -ESRCH; goto out_unlock; } - pcred = __task_cred(p); - if (si_fromuser(info) && - euid != pcred->suid && euid != pcred->uid && - uid != pcred->suid && uid != pcred->uid) { + if (si_fromuser(info) && !kill_as_cred_perm(cred, p)) { ret = -EPERM; goto out_unlock; } @@ -1384,7 +1392,7 @@ out_unlock: rcu_read_unlock(); return ret; } -EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); +EXPORT_SYMBOL_GPL(kill_pid_info_as_cred); /* * kill_something_info() interprets pid in interesting ways just like kill(2). @@ -1621,10 +1629,8 @@ bool do_notify_parent(struct task_struct *tsk, int sig) info.si_uid = __task_cred(tsk)->uid; rcu_read_unlock(); - info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, - tsk->signal->utime)); - info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, - tsk->signal->stime)); + info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime); + info.si_stime = cputime_to_clock_t(tsk->stime + tsk->signal->stime); info.si_status = tsk->exit_code & 0x7f; if (tsk->exit_code & 0x80) @@ -1986,8 +1992,6 @@ static bool do_signal_stop(int signr) */ if (!(sig->flags & SIGNAL_STOP_STOPPED)) sig->group_exit_code = signr; - else - WARN_ON_ONCE(!current->ptrace); sig->group_stop_count = 0; @@ -2351,8 +2355,15 @@ void exit_signals(struct task_struct *tsk) int group_stop = 0; sigset_t unblocked; + /* + * @tsk is about to have PF_EXITING set - lock out users which + * expect stable threadgroup. + */ + threadgroup_change_begin(tsk); + if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { tsk->flags |= PF_EXITING; + threadgroup_change_end(tsk); return; } @@ -2362,6 +2373,9 @@ void exit_signals(struct task_struct *tsk) * see wants_signal(), do_signal_stop(). */ tsk->flags |= PF_EXITING; + + threadgroup_change_end(tsk); + if (!signal_pending(tsk)) goto out; |