From 89833fab15d6017ba006a45b5af68caa067171a7 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Fri, 29 Mar 2019 22:46:51 +0100 Subject: [PATCH] x86/fpu: Fix __user annotations In save_xstate_epilog(), use __user when type-casting userspace pointers. In setup_sigcontext() and x32_setup_rt_frame(), cast the userspace pointers to 'unsigned long __user *' before writing into them. These pointers are originally '__u32 __user *' or '__u64 __user *', causing sparse to complain when a userspace pointer is written into them. The casts are okay because the pointers always point to pointer-sized values. Thanks to Luc Van Oostenryck and Al Viro for explaining this to me. Signed-off-by: Jann Horn Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Mathieu Desnoyers Cc: Mukesh Ojha Cc: Qiaowei Ren Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Cc: Will Deacon Cc: x86-ml Link: https://lkml.kernel.org/r/20190329214652.258477-3-jannh@google.com --- arch/x86/kernel/fpu/signal.c | 6 +++--- arch/x86/kernel/signal.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index f6a1d299627c..55b80de13ea5 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -92,13 +92,13 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame) return err; err |= __put_user(FP_XSTATE_MAGIC2, - (__u32 *)(buf + fpu_user_xstate_size)); + (__u32 __user *)(buf + fpu_user_xstate_size)); /* * Read the xfeatures which we copied (directly from the cpu or * from the state in task struct) to the user buffers. */ - err |= __get_user(xfeatures, (__u32 *)&x->header.xfeatures); + err |= __get_user(xfeatures, (__u32 __user *)&x->header.xfeatures); /* * For legacy compatible, we always set FP/SSE bits in the bit @@ -113,7 +113,7 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame) */ xfeatures |= XFEATURE_MASK_FPSSE; - err |= __put_user(xfeatures, (__u32 *)&x->header.xfeatures); + err |= __put_user(xfeatures, (__u32 __user *)&x->header.xfeatures); return err; } diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 08dfd4c1a4f9..b419e1a1a0ce 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -206,7 +206,7 @@ int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, put_user_ex(regs->ss, &sc->ss); #endif /* CONFIG_X86_32 */ - put_user_ex(fpstate, &sc->fpstate); + put_user_ex(fpstate, (unsigned long __user *)&sc->fpstate); /* non-iBCS2 extensions.. */ put_user_ex(mask, &sc->oldmask); @@ -569,7 +569,7 @@ static int x32_setup_rt_frame(struct ksignal *ksig, restorer = NULL; err |= -EFAULT; } - put_user_ex(restorer, &frame->pretcode); + put_user_ex(restorer, (unsigned long __user *)&frame->pretcode); } put_user_catch(err); err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,