From: Bernd Edlinger <bernd.edlinger@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/AM8PR10MB470871DEBD1DED081F9CC391E4389@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1198,11 +1198,11 @@ 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);
