From: Christophe Leroy christophe.leroy@csgroup.eu
commit 57fdfbce89137ae85cd5cef48be168040a47dd13 upstream.
Userspace Execution protection and fast syscall entry were implemented independently from each other and were both merged in kernel 5.2, leading to syscall entry missing userspace execution protection.
On syscall entry, execution of user space memory must be locked in the same way as on exception entry.
Fixes: b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/c65e105b63aaf74f91a14f845bc77192350b84a6.161279661... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/powerpc/kernel/entry_32.S | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -356,6 +356,9 @@ trace_syscall_entry_irq_off:
.globl transfer_to_syscall transfer_to_syscall: +#ifdef CONFIG_PPC_BOOK3S_32 + kuep_lock r11, r12 +#endif #ifdef CONFIG_TRACE_IRQFLAGS andi. r12,r9,MSR_EE beq- trace_syscall_entry_irq_off