[PATCH 3/4] arm64: Fix the hw_breakpoint range check

Frederic Weisbecker
2013-11-24T10:32:50Z

From: Oleg Nesterov <oleg@redhat.com>

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@redhat.com>
Fixes: 478fcb2cdb2351dcfc3fb23f42d76f4436ee4149
Cc: <stable@vger.kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
arch/arm64/kernel/hw_breakpoint.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index ff516f6..4bbbfde 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -293,7 +293,7 @@ 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