[PATCH] selinux: fix tty locking (b20c8122) · Commits · 戴 / test

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 <sds@tycho.nsa.gov> Acked-by:

Alan Cox <alan@redhat.com> Acked-by:

James Morris <jmorris@namei.org> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

security/selinux/hooks.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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. */

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