| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 31/42] arm64/ptrace: Preserve previous registers for short regset write - 2 | Date | Tue, 24 Jan 2017 08:55:41 +0100 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Dave Martin <Dave.Martin@arm.com>
commit 9dd73f72f218320c6c90da5f834996e7360dc227 upstream.
Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved.
Fixes: 766a85d7bc5d ("arm64: ptrace: add NT_ARM_SYSTEM_CALL regset") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <Will.Deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/arm64/kernel/ptrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -576,7 +576,8 @@ static int system_call_set(struct task_s unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - int syscallno, ret; + int syscallno = task_pt_regs(target)->syscallno; + int ret; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1); if (ret)
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