From: Eric Paris Date: Tue, 4 Nov 2008 20:18:26 +0000 (-0500) Subject: SELinux: hold tasklist_lock and siglock while waking wait_chldexit X-Git-Tag: v2.6.29-rc1~588^2^2~106 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=41d9f9c524a53477467b7e0111ff3d644198f191;p=linux-2.6-omap-h63xx.git SELinux: hold tasklist_lock and siglock while waking wait_chldexit SELinux has long been calling wake_up_interruptible() on current->parent->signal->wait_chldexit without holding any locks. It appears that this operation should hold the tasklist_lock to dereference current->parent and we should hold the siglock when waking up the signal->wait_chldexit. Signed-off-by: Eric Paris Signed-off-by: James Morris --- diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 03ff7db2a2c..5f21a514f58 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2268,7 +2268,9 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) struct rlimit *rlim, *initrlim; struct itimerval itimer; struct bprm_security_struct *bsec; + struct sighand_struct *psig; int rc, i; + unsigned long flags; tsec = current->security; bsec = bprm->security; @@ -2335,7 +2337,12 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) /* Wake up the parent if it is waiting so that it can recheck wait permission to the new task SID. */ + read_lock_irq(&tasklist_lock); + psig = current->parent->sighand; + spin_lock_irqsave(&psig->siglock, flags); wake_up_interruptible(¤t->parent->signal->wait_chldexit); + spin_unlock_irqrestore(&psig->siglock, flags); + read_unlock_irq(&tasklist_lock); } /* superblock security operations */