From: Dave Martin Dave.Martin@arm.com
This patch has been added to the stable tree. If you have any objections, please let us know.
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[ Upstream commit d614fd58a2834cfe4efa472c33c8f3ce2338b09b ]
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 Dave.Martin@arm.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- arch/mips/kernel/ptrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index 81a13fd56d13..2bea5db01b0b 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -484,7 +484,8 @@ 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));