From 2b2040af0b64cd93e5d4df2494c4486cf604090d Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 7 Sep 2012 18:21:44 +0100 Subject: [PATCH] ARM: 7526/1: traps: send SIGILL if get_user fails on undef handling path get_user may fail to load from the provided __user address due to an unhandled fault generated by the access. In the case of the undefined instruction trap, this results in failure to load the faulting instruction, in which case we should send SIGILL to the task rather than continue with potentially uninitialised data. Signed-off-by: Will Deacon Cc: stable@vger.kernel.org Signed-off-by: Russell King --- arch/arm/kernel/traps.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index f7945218b8c6..b0179b89a04c 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -420,20 +420,23 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) #endif instr = *(u32 *) pc; } else if (thumb_mode(regs)) { - get_user(instr, (u16 __user *)pc); + if (get_user(instr, (u16 __user *)pc)) + goto die_sig; if (is_wide_instruction(instr)) { unsigned int instr2; - get_user(instr2, (u16 __user *)pc+1); + if (get_user(instr2, (u16 __user *)pc+1)) + goto die_sig; instr <<= 16; instr |= instr2; } - } else { - get_user(instr, (u32 __user *)pc); + } else if (get_user(instr, (u32 __user *)pc)) { + goto die_sig; } if (call_undef_hook(regs, instr) == 0) return; +die_sig: #ifdef CONFIG_DEBUG_USER if (user_debug & UDBG_UNDEFINED) { printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", -- 2.20.1