From: Dave Martin Date: Mon, 27 Mar 2017 14:10:58 +0000 (+0100) Subject: mips/ptrace: Preserve previous registers for short regset write X-Git-Tag: Ubuntu-4.11.0-0.5~344^2~1 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=d614fd58a2834cfe4efa472c33c8f3ce2338b09b;p=mirror_ubuntu-artful-kernel.git mips/ptrace: Preserve previous registers for short regset write Ensure that if userspace supplies insufficient data to PTRACE_SETREGSET to fill all the registers, the thread's old registers are preserved. Signed-off-by: Dave Martin Signed-off-by: Linus Torvalds --- diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index c8ba26072132..5d2498eb2340 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -485,7 +485,8 @@ static int fpr_set(struct task_struct *target, &target->thread.fpu, 0, sizeof(elf_fpregset_t)); - for (i = 0; i < NUM_FPU_REGS; i++) { + BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t)); + for (i = 0; i < NUM_FPU_REGS && count >= sizeof(elf_fpreg_t); i++) { err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpr_val, i * sizeof(elf_fpreg_t), (i + 1) * sizeof(elf_fpreg_t));