Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH v3 06/11] rlimits: do security check under task_lock | Date | Mon, 10 May 2010 20:00:46 +0200 |
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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@suse.cz> Acked-by: 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 eb21661..9e9a3a7 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1277,7 +1277,7 @@ int do_setrlimit(struct task_struct *tsk, unsigned int resource, struct rlimit *new_rlim) { struct rlimit *old_rlim; - int retval; + int retval = 0; if (resource >= RLIM_NLIMITS) return -EINVAL; @@ -1293,10 +1293,6 @@ int do_setrlimit(struct task_struct *tsk, unsigned int resource, goto out; } - 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 @@ -1309,11 +1305,13 @@ int do_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) -- 1.7.1
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