diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/entry/syscall_user_dispatch.c | 12 | ||||
| -rw-r--r-- | kernel/kthread.c | 2 | ||||
| -rw-r--r-- | kernel/reboot.c | 1 | ||||
| -rw-r--r-- | kernel/signal.c | 34 |
4 files changed, 33 insertions, 16 deletions
diff --git a/kernel/entry/syscall_user_dispatch.c b/kernel/entry/syscall_user_dispatch.c index c240302f56e2..4508201847d2 100644 --- a/kernel/entry/syscall_user_dispatch.c +++ b/kernel/entry/syscall_user_dispatch.c @@ -47,14 +47,18 @@ bool syscall_user_dispatch(struct pt_regs *regs) * access_ok() is performed once, at prctl time, when * the selector is loaded by userspace. */ - if (unlikely(__get_user(state, sd->selector))) - do_exit(SIGSEGV); + if (unlikely(__get_user(state, sd->selector))) { + force_fatal_sig(SIGSEGV); + return true; + } if (likely(state == SYSCALL_DISPATCH_FILTER_ALLOW)) return false; - if (state != SYSCALL_DISPATCH_FILTER_BLOCK) - do_exit(SIGSYS); + if (state != SYSCALL_DISPATCH_FILTER_BLOCK) { + force_fatal_sig(SIGSYS); + return true; + } } sd->on_dispatch = true; diff --git a/kernel/kthread.c b/kernel/kthread.c index 4a4d7092a2d8..7113003fab63 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -433,7 +433,7 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), * If thread is going to be bound on a particular cpu, give its node * in @node, to get NUMA affinity for kthread stack, or else give NUMA_NO_NODE. * When woken, the thread will run @threadfn() with @data as its - * argument. @threadfn() can either call do_exit() directly if it is a + * argument. @threadfn() can either return directly if it is a * standalone thread for which no one will call kthread_stop(), or * return when 'kthread_should_stop()' is true (which means * kthread_stop() has been called). The return value should be zero diff --git a/kernel/reboot.c b/kernel/reboot.c index f7440c0c7e43..d6e0f9fb7f04 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -359,7 +359,6 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, case LINUX_REBOOT_CMD_HALT: kernel_halt(); do_exit(0); - panic("cannot halt"); case LINUX_REBOOT_CMD_POWER_OFF: kernel_power_off(); diff --git a/kernel/signal.c b/kernel/signal.c index 6f3476dc7873..7c4b7ae714d4 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1323,6 +1323,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool blocked = sigismember(&t->blocked, sig); if (blocked || ignored || sigdfl) { action->sa.sa_handler = SIG_DFL; + action->sa.sa_flags |= SA_IMMUTABLE; if (blocked) { sigdelset(&t->blocked, sig); recalc_sigpending_and_wake(t); @@ -1649,6 +1650,19 @@ void force_sig(int sig) } EXPORT_SYMBOL(force_sig); +void force_fatal_sig(int sig) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = sig; + info.si_errno = 0; + info.si_code = SI_KERNEL; + info.si_pid = 0; + info.si_uid = 0; + force_sig_info_to_task(&info, current, true); +} + /* * When things go south during signal handling, we * will force a SIGSEGV. And if the signal that caused @@ -1657,15 +1671,10 @@ EXPORT_SYMBOL(force_sig); */ void force_sigsegv(int sig) { - struct task_struct *p = current; - - if (sig == SIGSEGV) { - unsigned long flags; - spin_lock_irqsave(&p->sighand->siglock, flags); - p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; - spin_unlock_irqrestore(&p->sighand->siglock, flags); - } - force_sig(SIGSEGV); + if (sig == SIGSEGV) + force_fatal_sig(SIGSEGV); + else + force_sig(SIGSEGV); } int force_sig_fault_to_task(int sig, int code, void __user *addr @@ -2704,7 +2713,8 @@ relock: if (!signr) break; /* will return 0 */ - if (unlikely(current->ptrace) && signr != SIGKILL) { + if (unlikely(current->ptrace) && (signr != SIGKILL) && + !(sighand->action[signr -1].sa.sa_flags & SA_IMMUTABLE)) { signr = ptrace_signal(signr, &ksig->info); if (!signr) continue; @@ -4054,6 +4064,10 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) k = &p->sighand->action[sig-1]; spin_lock_irq(&p->sighand->siglock); + if (k->sa.sa_flags & SA_IMMUTABLE) { + spin_unlock_irq(&p->sighand->siglock); + return -EINVAL; + } if (oact) *oact = *k; |