From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Frederic Weisbecker To: LKML Cc: Oleg Nesterov , , Frederic Weisbecker Subject: [PATCH 2/4] x86: Fix the hw_breakpoint range check Date: Sun, 24 Nov 2013 11:32:49 +0100 Message-Id: <1385289171-3411-3-git-send-email-fweisbec@gmail.com> In-Reply-To: <1385289171-3411-1-git-send-email-fweisbec@gmail.com> References: <1385289171-3411-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Oleg Nesterov arch_check_bp_in_kernelspace() tries to avoid the overflow and does 2 TASK_SIZE checks but it needs OR, not AND. Consider va = TASK_SIZE -1 and len = 2 case. Note: TASK_SIZE doesn't look right at least on x86, I think it should be replaced by TASK_SIZE_MAX. Signed-off-by: Oleg Nesterov Fixes: 0067f1297241ea567f2b22a455519752d70fcca9 Cc: Signed-off-by: Frederic Weisbecker --- arch/x86/kernel/hw_breakpoint.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c index f66ff16..1131c1f 100644 --- a/arch/x86/kernel/hw_breakpoint.c +++ b/arch/x86/kernel/hw_breakpoint.c @@ -200,7 +200,7 @@ int arch_check_bp_in_kernelspace(struct perf_event *bp) va = info->address; len = get_hbp_len(info->len); - return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE); + return (va >= TASK_SIZE) || ((va + len - 1) >= TASK_SIZE); } int arch_bp_generic_fields(int x86_len, int x86_type, -- 1.8.3.1