From ee50036b25be62e4abbac46665f410b887b66130 Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Fri, 29 Jul 2022 04:40:16 +0100 Subject: [PATCH] ARM: 9221/1: traps: print un-hashed user pc on undefined instruction When user undefined instruction debug is enabled pc value is hashed like kernel pointers for security reason. But the security benefit of this hash is very limited because the code goes on to call __show_regs() that prints the plain pointer value. pc is a user pointer anyway, so the kernel does not leak anything. The only result is confusion about the difference between the pc value on the first printed line, and the value that __show_regs() prints. Always print the plain value of pc. Signed-off-by: Baruch Siach Signed-off-by: Russell King (Oracle) --- arch/arm/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 9283dc65be31b..82fde11d6b8df 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -487,7 +487,7 @@ asmlinkage void do_undefinstr(struct pt_regs *regs) die_sig: #ifdef CONFIG_DEBUG_USER if (user_debug & UDBG_UNDEFINED) { - pr_info("%s (%d): undefined instruction: pc=%p\n", + pr_info("%s (%d): undefined instruction: pc=%px\n", current->comm, task_pid_nr(current), pc); __show_regs(regs); dump_instr(KERN_INFO, regs); -- 2.30.2