diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index e5f8aea78ff..7fe874d12fa 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -10,7 +10,6 @@ * to allow signals to be sent reliably. */ -#include <linux/config.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/smp_lock.h> @@ -23,12 +22,12 @@ #include <linux/syscalls.h> #include <linux/ptrace.h> #include <linux/signal.h> -#include <linux/audit.h> #include <linux/capability.h> #include <asm/param.h> #include <asm/uaccess.h> #include <asm/unistd.h> #include <asm/siginfo.h> +#include "audit.h" /* audit_signal_info() */ /* * SLAB caches for signal bits. @@ -584,7 +583,7 @@ static int check_kill_permission(int sig, struct siginfo *info, && !capable(CAP_KILL)) return error; - error = security_task_kill(t, info, sig); + error = security_task_kill(t, info, sig, 0); if (!error) audit_signal_info(sig, t); /* Let audit system see the signal */ return error; @@ -1107,7 +1106,7 @@ kill_proc_info(int sig, struct siginfo *info, pid_t pid) /* like kill_proc_info(), but doesn't use uid/euid of "current" */ int kill_proc_info_as_uid(int sig, struct siginfo *info, pid_t pid, - uid_t uid, uid_t euid) + uid_t uid, uid_t euid, u32 secid) { int ret = -EINVAL; struct task_struct *p; @@ -1127,6 +1126,9 @@ int kill_proc_info_as_uid(int sig, struct siginfo *info, pid_t pid, ret = -EPERM; goto out_unlock; } + ret = security_task_kill(p, info, sig, secid); + if (ret) + goto out_unlock; if (sig && p->sighand) { unsigned long flags; spin_lock_irqsave(&p->sighand->siglock, flags); @@ -1531,6 +1533,35 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why) spin_unlock_irqrestore(&sighand->siglock, flags); } +static inline int may_ptrace_stop(void) +{ + if (!likely(current->ptrace & PT_PTRACED)) + return 0; + + if (unlikely(current->parent == current->real_parent && + (current->ptrace & PT_ATTACHED))) + return 0; + + if (unlikely(current->signal == current->parent->signal) && + unlikely(current->signal->flags & SIGNAL_GROUP_EXIT)) + return 0; + + /* + * Are we in the middle of do_coredump? + * If so and our tracer is also part of the coredump stopping + * is a deadlock situation, and pointless because our tracer + * is dead so don't allow us to stop. + * If SIGKILL was already sent before the caller unlocked + * ->siglock we must see ->core_waiters != 0. Otherwise it + * is safe to enter schedule(). + */ + if (unlikely(current->mm->core_waiters) && + unlikely(current->mm == current->parent->mm)) + return 0; + + return 1; +} + /* * This must be called with current->sighand->siglock held. * @@ -1559,11 +1590,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info) spin_unlock_irq(¤t->sighand->siglock); try_to_freeze(); read_lock(&tasklist_lock); - if (likely(current->ptrace & PT_PTRACED) && - likely(current->parent != current->real_parent || - !(current->ptrace & PT_ATTACHED)) && - (likely(current->parent->signal != current->signal) || - !unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) { + if (may_ptrace_stop()) { do_notify_parent_cldstop(current, CLD_TRAPPED); read_unlock(&tasklist_lock); schedule(); |