From 3650e1d9284926be67e368707a9a2276fb77a167 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 24 Jul 2018 05:20:48 -0700 Subject: x86: Update vfork to pop shadow stack The shadow stack prevents us from pushing the saved return PC onto the stack and returning normally. Instead we pop the shadow stack and return directly. This is the safest way to return and ensures any stack manipulations done by the vfork'd child doesn't cause the parent to terminate when CET is enabled. Reviewed-by: Carlos O'Donell * sysdeps/unix/sysv/linux/i386/vfork.S (SYSCALL_ERROR_HANDLER): Redefine if shadow stack is enabled. (SYSCALL_ERROR_LABEL): Likewise. (__vfork): Pop shadow stack and jump back to to caller directly when shadow stack is in use. * sysdeps/unix/sysv/linux/x86_64/vfork.S (SYSCALL_ERROR_HANDLER): Redefine if shadow stack is enabled. (SYSCALL_ERROR_LABEL): Likewise. (__vfork): Pop shadow stack and jump back to to caller directly when shadow stack is in use. --- ChangeLog | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'ChangeLog') diff --git a/ChangeLog b/ChangeLog index 2a1a53d9df..8b892eb686 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,16 @@ +2018-07-24 H.J. Lu + + * sysdeps/unix/sysv/linux/i386/vfork.S (SYSCALL_ERROR_HANDLER): + Redefine if shadow stack is enabled. + (SYSCALL_ERROR_LABEL): Likewise. + (__vfork): Pop shadow stack and jump back to to caller directly + when shadow stack is in use. + * sysdeps/unix/sysv/linux/x86_64/vfork.S (SYSCALL_ERROR_HANDLER): + Redefine if shadow stack is enabled. + (SYSCALL_ERROR_LABEL): Likewise. + (__vfork): Pop shadow stack and jump back to to caller directly + when shadow stack is in use. + 2018-07-24 H.J. Lu * sysdeps/x86_64/tst-quadmod1.S (func): Add endbr64 if IBT is -- cgit v1.2.3