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-rw-r--r--fs/exec.c155
1 files changed, 85 insertions, 70 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 3a79d97ac234..8344ba73a2a6 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -22,7 +22,6 @@
* formats.
*/
-#include <linux/config.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/mman.h>
@@ -49,6 +48,7 @@
#include <linux/rmap.h>
#include <linux/acct.h>
#include <linux/cn_proc.h>
+#include <linux/audit.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@@ -665,8 +665,6 @@ static int de_thread(struct task_struct *tsk)
* and to assume its PID:
*/
if (!thread_group_leader(current)) {
- struct dentry *proc_dentry1, *proc_dentry2;
-
/*
* Wait for the thread group leader to be a zombie.
* It should already be zombie at this point, most
@@ -688,10 +686,6 @@ static int de_thread(struct task_struct *tsk)
*/
current->start_time = leader->start_time;
- spin_lock(&leader->proc_lock);
- spin_lock(&current->proc_lock);
- proc_dentry1 = proc_pid_unhash(current);
- proc_dentry2 = proc_pid_unhash(leader);
write_lock_irq(&tasklist_lock);
BUG_ON(leader->tgid != current->tgid);
@@ -712,7 +706,7 @@ static int de_thread(struct task_struct *tsk)
attach_pid(current, PIDTYPE_PID, current->pid);
attach_pid(current, PIDTYPE_PGID, current->signal->pgrp);
attach_pid(current, PIDTYPE_SID, current->signal->session);
- list_add_tail_rcu(&current->tasks, &init_task.tasks);
+ list_replace_rcu(&leader->tasks, &current->tasks);
current->group_leader = current;
leader->group_leader = current;
@@ -720,7 +714,6 @@ static int de_thread(struct task_struct *tsk)
/* Reduce leader to a thread */
detach_pid(leader, PIDTYPE_PGID);
detach_pid(leader, PIDTYPE_SID);
- list_del_init(&leader->tasks);
current->exit_signal = SIGCHLD;
@@ -728,10 +721,6 @@ static int de_thread(struct task_struct *tsk)
leader->exit_state = EXIT_DEAD;
write_unlock_irq(&tasklist_lock);
- spin_unlock(&leader->proc_lock);
- spin_unlock(&current->proc_lock);
- proc_pid_flush(proc_dentry1);
- proc_pid_flush(proc_dentry2);
}
/*
@@ -865,7 +854,6 @@ int flush_old_exec(struct linux_binprm * bprm)
bprm->mm = NULL; /* We're using it now */
/* This is the point of no return */
- steal_locks(files);
put_files_struct(files);
current->sas_ss_sp = current->sas_ss_size = 0;
@@ -1085,6 +1073,11 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
/* kernel module loader fixup */
/* so we don't try to load run modprobe in kernel space. */
set_fs(USER_DS);
+
+ retval = audit_bprm(bprm);
+ if (retval)
+ return retval;
+
retval = -ENOENT;
for (try=0; try<2; try++) {
read_lock(&binfmt_lock);
@@ -1374,67 +1367,102 @@ static void format_corename(char *corename, const char *pattern, long signr)
*out_ptr = 0;
}
-static void zap_threads (struct mm_struct *mm)
+static void zap_process(struct task_struct *start)
{
- struct task_struct *g, *p;
- struct task_struct *tsk = current;
- struct completion *vfork_done = tsk->vfork_done;
- int traced = 0;
+ struct task_struct *t;
- /*
- * Make sure nobody is waiting for us to release the VM,
- * otherwise we can deadlock when we wait on each other
- */
- if (vfork_done) {
- tsk->vfork_done = NULL;
- complete(vfork_done);
- }
+ start->signal->flags = SIGNAL_GROUP_EXIT;
+ start->signal->group_stop_count = 0;
- read_lock(&tasklist_lock);
- do_each_thread(g,p)
- if (mm == p->mm && p != tsk) {
- force_sig_specific(SIGKILL, p);
- mm->core_waiters++;
- if (unlikely(p->ptrace) &&
- unlikely(p->parent->mm == mm))
- traced = 1;
+ t = start;
+ do {
+ if (t != current && t->mm) {
+ t->mm->core_waiters++;
+ sigaddset(&t->pending.signal, SIGKILL);
+ signal_wake_up(t, 1);
}
- while_each_thread(g,p);
+ } while ((t = next_thread(t)) != start);
+}
- read_unlock(&tasklist_lock);
+static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
+ int exit_code)
+{
+ struct task_struct *g, *p;
+ unsigned long flags;
+ int err = -EAGAIN;
+
+ spin_lock_irq(&tsk->sighand->siglock);
+ if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) {
+ tsk->signal->group_exit_code = exit_code;
+ zap_process(tsk);
+ err = 0;
+ }
+ spin_unlock_irq(&tsk->sighand->siglock);
+ if (err)
+ return err;
- if (unlikely(traced)) {
- /*
- * We are zapping a thread and the thread it ptraces.
- * If the tracee went into a ptrace stop for exit tracing,
- * we could deadlock since the tracer is waiting for this
- * coredump to finish. Detach them so they can both die.
- */
- write_lock_irq(&tasklist_lock);
- do_each_thread(g,p) {
- if (mm == p->mm && p != tsk &&
- p->ptrace && p->parent->mm == mm) {
- __ptrace_detach(p, 0);
+ if (atomic_read(&mm->mm_users) == mm->core_waiters + 1)
+ goto done;
+
+ rcu_read_lock();
+ for_each_process(g) {
+ if (g == tsk->group_leader)
+ continue;
+
+ p = g;
+ do {
+ if (p->mm) {
+ if (p->mm == mm) {
+ /*
+ * p->sighand can't disappear, but
+ * may be changed by de_thread()
+ */
+ lock_task_sighand(p, &flags);
+ zap_process(p);
+ unlock_task_sighand(p, &flags);
+ }
+ break;
}
- } while_each_thread(g,p);
- write_unlock_irq(&tasklist_lock);
+ } while ((p = next_thread(p)) != g);
}
+ rcu_read_unlock();
+done:
+ return mm->core_waiters;
}
-static void coredump_wait(struct mm_struct *mm)
+static int coredump_wait(int exit_code)
{
- DECLARE_COMPLETION(startup_done);
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ struct completion startup_done;
+ struct completion *vfork_done;
int core_waiters;
+ init_completion(&mm->core_done);
+ init_completion(&startup_done);
mm->core_startup_done = &startup_done;
- zap_threads(mm);
- core_waiters = mm->core_waiters;
+ core_waiters = zap_threads(tsk, mm, exit_code);
up_write(&mm->mmap_sem);
+ if (unlikely(core_waiters < 0))
+ goto fail;
+
+ /*
+ * Make sure nobody is waiting for us to release the VM,
+ * otherwise we can deadlock when we wait on each other
+ */
+ vfork_done = tsk->vfork_done;
+ if (vfork_done) {
+ tsk->vfork_done = NULL;
+ complete(vfork_done);
+ }
+
if (core_waiters)
wait_for_completion(&startup_done);
+fail:
BUG_ON(mm->core_waiters);
+ return core_waiters;
}
int do_coredump(long signr, int exit_code, struct pt_regs * regs)
@@ -1468,22 +1496,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
}
mm->dumpable = 0;
- retval = -EAGAIN;
- spin_lock_irq(&current->sighand->siglock);
- if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
- current->signal->flags = SIGNAL_GROUP_EXIT;
- current->signal->group_exit_code = exit_code;
- current->signal->group_stop_count = 0;
- retval = 0;
- }
- spin_unlock_irq(&current->sighand->siglock);
- if (retval) {
- up_write(&mm->mmap_sem);
+ retval = coredump_wait(exit_code);
+ if (retval < 0)
goto fail;
- }
-
- init_completion(&mm->core_done);
- coredump_wait(mm);
/*
* Clear any false indication of pending signals that might
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.