lkml.org 
[lkml]   [2009]   [Nov]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 02/16] core: do security check under task_lock
Date
Do security_task_setrlimit under task_lock. Other tasks may
change limits under our hands while we are checking limits
inside the function. From now on, they can't.

Signed-off-by: Jiri Slaby <jslaby@novell.com>
Cc: James Morris <jmorris@namei.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
---
kernel/sys.c | 16 +++++++---------
1 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index 605ab9c..0f86199 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1243,7 +1243,7 @@ int setrlimit(struct task_struct *tsk, unsigned int resource,
struct rlimit *new_rlim)
{
struct rlimit *old_rlim;
- int retval;
+ int retval = 0;

if (new_rlim->rlim_cur > new_rlim->rlim_max)
return -EINVAL;
@@ -1260,10 +1260,6 @@ int setrlimit(struct task_struct *tsk, unsigned int resource,
}
}

- retval = security_task_setrlimit(tsk, resource, new_rlim);
- if (retval)
- goto out;
-
if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
/*
* The caller is asking for an immediate RLIMIT_CPU
@@ -1276,11 +1272,13 @@ int setrlimit(struct task_struct *tsk, unsigned int resource,

old_rlim = tsk->signal->rlim + resource;
task_lock(tsk->group_leader);
- if ((new_rlim->rlim_max <= old_rlim->rlim_max) ||
- capable(CAP_SYS_RESOURCE))
- *old_rlim = *new_rlim;
- else
+ if ((new_rlim->rlim_max > old_rlim->rlim_max) &&
+ !capable(CAP_SYS_RESOURCE))
retval = -EPERM;
+ if (!retval)
+ retval = security_task_setrlimit(tsk, resource, new_rlim);
+ if (!retval)
+ *old_rlim = *new_rlim;
task_unlock(tsk->group_leader);

if (retval || resource != RLIMIT_CPU)
--
1.6.4.2


\
 
 \ /
  Last update: 2009-11-18 15:55    [from the cache]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and my Meterkast|Read the blog