diff mbox series

[5.10,609/663] powerpc/32s: Add missing call to kuep_lock on syscall entry

Message ID 20210301161211.978994505@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman March 1, 2021, 4:14 p.m. UTC 
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/c65e105b63aaf74f91a14f845bc77192350b84a6.1612796617.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/powerpc/kernel/entry_32.S |    3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -347,6 +347,9 @@  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