[PATCH 1/4] arm: Fix the hw_breakpoint range check

[Frederic Weisbecker]

From: Oleg Nesterov <oleg@xxxxxxxxxx>

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.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Fixes: f81ef4a920c8e1af75adf9f15042c2daa49d3cb3
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
 arch/arm/kernel/hw_breakpoint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 3d44660..8b38001 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -465,7 +465,7 @@ int arch_check_bp_in_kernelspace(struct perf_event *bp)
 	va = info->address;
 	len = get_hbp_len(info->ctrl.len);
 
-	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+	return (va >= TASK_SIZE) || ((va + len - 1) >= TASK_SIZE);
 }
 
 /*
-- 
1.8.3.1

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