Messages in this thread Patch in this message |  | | From | Jiri Slaby <> | | Subject | [PATCH 02/16] core: do security check under task_lock | | Date | Wed, 18 Nov 2009 15:51:48 +0100 |
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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
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