qubes-linux-kernel/patches.suse/rlim-0019-core-allow-setrlimit-to-non-current-tasks.patch
2010-07-07 13:12:45 +02:00

57 lines
1.6 KiB
Diff

From a35547da680829ce9036a476678a5fd4bfa59a6b Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jirislaby@gmail.com>
Date: Fri, 28 Aug 2009 14:08:17 +0200
Subject: [PATCH] core: allow setrlimit to non-current tasks
References: FATE#305733
Patch-mainline: no (later)
Add locking to allow setrlimit accept task parameter other than
current.
Namely, lock tasklist_lock for read and check whether the task
structure has sighand non-null. Do all the signal processing under
that lock still held.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Oleg Nesterov <oleg@redhat.com>
---
kernel/sys.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1302,6 +1302,7 @@ SYSCALL_DEFINE2(old_getrlimit, unsigned
#endif
+/* make sure you are allowed to change @tsk limits before calling this */
int do_setrlimit(struct task_struct *tsk, unsigned int resource,
struct rlimit *new_rlim)
{
@@ -1315,9 +1316,16 @@ int do_setrlimit(struct task_struct *tsk
if (resource == RLIMIT_NOFILE && new_rlim->rlim_max > sysctl_nr_open)
return -EPERM;
+ /* protect tsk->signal and tsk->sighand from disappearing */
+ read_lock(&tasklist_lock);
+ if (!tsk->sighand) {
+ retval = -ESRCH;
+ goto out;
+ }
+
retval = security_task_setrlimit(tsk, resource, new_rlim);
if (retval)
- return retval;
+ goto out;
if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
/*
@@ -1352,6 +1360,7 @@ int do_setrlimit(struct task_struct *tsk
update_rlimit_cpu(tsk, new_rlim->rlim_cur);
out:
+ read_unlock(&tasklist_lock);
return retval;
}