The patch titled
wait_task_stopped(): don't use task_pid_nr_ns() lockless
has been removed from the -mm tree. Its filename was
wait_task_stopped-dont-use-task_pid_nr_ns-lockless.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: wait_task_stopped(): don't use task_pid_nr_ns() lockless
From: Oleg Nesterov <oleg@xxxxxxxxxx>
wait_task_stopped(WNOWAIT) does task_pid_nr_ns() without tasklist/rcu lock,
we can read an already freed memory. Use the cached pid_t value.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Looks-good-to: Roland McGrath <roland@xxxxxxxxxx>
Acked-by: Pavel Emelyanov <xemul@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/exit.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff -puN kernel/exit.c~wait_task_stopped-dont-use-task_pid_nr_ns-lockless kernel/exit.c
--- a/kernel/exit.c~wait_task_stopped-dont-use-task_pid_nr_ns-lockless
+++ a/kernel/exit.c
@@ -1357,7 +1357,7 @@ static int wait_task_stopped(struct task
int __user *stat_addr, struct rusage __user *ru)
{
int retval, exit_code;
- struct pid_namespace *ns;
+ pid_t pid;
if (!p->exit_code)
return 0;
@@ -1376,12 +1376,11 @@ static int wait_task_stopped(struct task
* keep holding onto the tasklist_lock while we call getrusage and
* possibly take page faults for user memory.
*/
- ns = current->nsproxy->pid_ns;
+ pid = task_pid_nr_ns(p, current->nsproxy->pid_ns);
get_task_struct(p);
read_unlock(&tasklist_lock);
if (unlikely(noreap)) {
- pid_t pid = task_pid_nr_ns(p, ns);
uid_t uid = p->uid;
int why = (p->ptrace & PT_PTRACED) ? CLD_TRAPPED : CLD_STOPPED;
@@ -1451,11 +1450,11 @@ bail_ref:
if (!retval && infop)
retval = put_user(exit_code, &infop->si_status);
if (!retval && infop)
- retval = put_user(task_pid_nr_ns(p, ns), &infop->si_pid);
+ retval = put_user(pid, &infop->si_pid);
if (!retval && infop)
retval = put_user(p->uid, &infop->si_uid);
if (!retval)
- retval = task_pid_nr_ns(p, ns);
+ retval = pid;
put_task_struct(p);
BUG_ON(!retval);
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
git-x86.patch
use-__set_task_state-for-traced-stopped-tasks.patch
add-task_wakekill.patch
do_wait-remove-one-else-if-branch.patch
proc-implement-proc_single_file_operations.patch
proc-rewrite-do_task_stat-to-correctly-handle-pid-namespaces.patch
proc-seqfile-convert-proc_pid_statm.patch
proc-proper-pidns-handling-for-proc-self.patch
proc-fix-the-threaded-proc-self.patch
kill-pt_attached.patch
kill-my_ptrace_child.patch
ptrace_check_attach-remove-unneeded-signal-=-null-check.patch
ptrace_stop-fix-the-race-with-ptrace-detachattach.patch
wait_task_stopped-simplify-and-fix-races-with-sigcont-sigkill-untrace.patch
do_wait-factor-out-retval-=-0-checks.patch
ptrace_stop-fix-racy-nonstop_code-setting.patch
wait_task_stopped-remove-unneeded-delay_group_leader-check.patch
do_wait-cleanup-delay_group_leader-usage.patch
do_wait-fix-security-checks.patch
do_wait-fix-security-checks-fix.patch
wait_task_continued-zombie-dont-use-task_pid_nr_ns-lockless.patch
wait_task_zombie-remove-exit_state-exit_signal-checks-for-wnowait.patch
sys_setpgid-simplify-pid-ns-interaction.patch
fix-setsid-for-sub-namespace-sbin-init.patch
teach-set_special_pids-to-use-struct-pid.patch
move-daemonized-kernel-threads-into-the-swappers-session.patch
start-the-global-sbin-init-with-00-special-pids.patch
-
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