From b20c8122a3204496fca8b5343c93b60fe11dad04 Mon Sep 17 00:00:00 2001 From: Stephen Smalley Date: Mon, 25 Sep 2006 23:32:03 -0700 Subject: [PATCH] [PATCH] selinux: fix tty locking Take tty_mutex when accessing ->signal->tty in selinux code. Noted by Alan Cox. Longer term, we are looking at refactoring the code to provide better encapsulation of the tty layer, but this is a simple fix that addresses the immediate bug. Signed-off-by: Stephen Smalley Acked-by: Alan Cox Acked-by: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 55cec4d6f117..e4d81a42fca4 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1689,10 +1689,12 @@ static inline void flush_unauthorized_files(struct files_struct * files) { struct avc_audit_data ad; struct file *file, *devnull = NULL; - struct tty_struct *tty = current->signal->tty; + struct tty_struct *tty; struct fdtable *fdt; long j = -1; + mutex_lock(&tty_mutex); + tty = current->signal->tty; if (tty) { file_list_lock(); file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list); @@ -1712,6 +1714,7 @@ static inline void flush_unauthorized_files(struct files_struct * files) } file_list_unlock(); } + mutex_unlock(&tty_mutex); /* Revalidate access to inherited open files. */