From: Bernd Edlinger bernd.edlinger@hotmail.de
commit 5bf2fedca8f59379025b0d52f917b9ddb9bfe17e upstream.
unshare_sighand should only access oldsighand->action while holding oldsighand->siglock, to make sure that newsighand->action is in a consistent state.
Signed-off-by: Bernd Edlinger bernd.edlinger@hotmail.de Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kees Cook keescook@chromium.org Link: https://lore.kernel.org/r/AM8PR10MB470871DEBD1DED081F9CC391E4389@AM8PR10MB47... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/exec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/exec.c +++ b/fs/exec.c @@ -1196,11 +1196,11 @@ static int unshare_sighand(struct task_s return -ENOMEM;
refcount_set(&newsighand->count, 1); - memcpy(newsighand->action, oldsighand->action, - sizeof(newsighand->action));
write_lock_irq(&tasklist_lock); spin_lock(&oldsighand->siglock); + memcpy(newsighand->action, oldsighand->action, + sizeof(newsighand->action)); rcu_assign_pointer(me->sighand, newsighand); spin_unlock(&oldsighand->siglock); write_unlock_irq(&tasklist_lock);