lkml.org 
[lkml]   [2011]   [Dec]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v2 -next] proc: fix task_struct memleak
proc_pid_permission() doesn't put task_struct on every /proc/$pid/
access. A demo from Hugh Dickins:

while :; do ps; grep KernelStack /proc/meminfo; sleep 1; done

Reported-by: Hugh Dickins <hughd@google.com>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
---
This is a patch against a hidepid patchset from -mm.

fs/proc/base.c | 9 +++++++--
1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8caf5cb..c2b38bc 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -646,9 +646,14 @@ static bool has_pid_permissions(struct pid_namespace *pid,
static int proc_pid_permission(struct inode *inode, int mask)
{
struct pid_namespace *pid = inode->i_sb->s_fs_info;
- struct task_struct *task = get_proc_task(inode);
+ struct task_struct *task;
+ bool has_perms;
+
+ task = get_proc_task(inode);
+ has_perms = has_pid_permissions(pid, task, 1);
+ put_task_struct(task);

- if (!has_pid_permissions(pid, task, 1)) {
+ if (!has_perms) {
if (pid->hide_pid == 2) {
/*
* Let's make getdents(), stat(), and open()
--
1.7.0.4


\
 
 \ /
  Last update: 2011-12-12 12:41    [W:0.031 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site