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

From: Frederic Weisbecker
Date: Sun Nov 24 2013 - 05:33:32 EST


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: 478fcb2cdb2351dcfc3fb23f42d76f4436ee4149
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/